SciHawks

Happy Halloween! I hope that you have more treats than tricks tonight and that you are able to maintain homeostasis after you eat your candy.
Reminder: Extra help in Room 301 tomorrow at about 8AM.

Bio- Posted on Blackboard is the unit objectives/questions review sheet. I will hand out a hard copy of these questions in class, tomorrow but you can get a head-start on the questions, after your festivities.
We reviewed the stages of mitosis and then we focused on, in great detail, what happens to the DNA molecules during the S phase of interphase. We also related DNA replication to the chromosome showing that, when DNA replicates, you STILL have the SAME number of chromosomes but the chromosomes become DOUBLE stranded, made up of identical sister chromatids joined at their centromere.
Eventually, during anaphase of mitosis, the centromeres double and the two sister chromatids are pulled apart by the spindle fibers thus, doubling the number of chromosomes; half of these chromosomes will go to one daughter cell and the other matching half of the chromosomes will go to the other daughter cell so that there is no net gain or loss of DNA/genetic information as the parent cell BECOMES the two daughter cells.
Tomorrow, we will review for Friday's exam. I will again repeatedly show you all how to take a test and I expect EVERY student to follow these always helpful, never harmful test-taking techniques. I also expect to see any students who are not doing well at extra help tomorrow, though all students are welcome, naturally. If you are not doing well, one of the main reasons for your lack of success is your lack of getting any or enough extra help. Given that about 5 students have EVER come to extra help, many of you need to take responsibility for your preparation and performance and learn from your past mistakes. Do not make excuses; get help and get the job done.
If you think that you are fully prepared for a test but are not doing well, show me your answers to all of the unit objective questions BEFORE each test, when I can help you. If they are all correct and detailed responses, it is extremely unlikely (practically impossible) for you to not get a great grade. If your answers are inaccurate and/or sketchy, or not even done, then you have not properly prepared for the test and that will account for your poor performance and lack of understanding. One of your most important jobs as a student is to make sure that you are prepared for each exam.

Chem 7/8- we delved into Graham's (like the crackers) Law, which state the relationship between the relative masses of gas molecules and their respective rates of diffusion and effusion. Graham found that, at the same temperature and pressure, the heavier the gas, the slower its rate of effusion/diffusion and the lighter the gas, the faster its rate of effusion/diffusion.
We explained this phenomenon by looking at the Kelvin Temperature - average kinetic energy connection of Kinetic Molecular Theory. At the same temperature, any two samples of gas molecules will have the SAME average kinetic energy BUT, there are TWO factors that contribute to kinetic energy: velocity AND mass. So, if two molecules have the same KE, the heavier one MUST be going slower (thus diffusing slower) and the lighter one must be going faster (thus diffusing faster). This accounts for Graham's "empirical" (EXPERIMENTALLY found, not just theoretically predicted!) discovery.
We saw how to calculate the relative masses of molecules by using the "atomic mass" numbers listed in the Periodic Table. For example, N= 14.3 atomic mass units and H= 1.0 atomic mass units so, ammonia, NH3 has an atomic mass of 17.3 (one N and three H's). Carbon dioxide, CO2, has an atomic mass of 44.0 atomic mass units
( one C = 12.0 amu's and two O's = 2 x 16.0 amu's) = 44.0 amu ; so, under the same conditions (T and P), ammonia will diffuse/effuse faster than carbon dioxide!
We then did a lab that showed one of the gas laws can be applied in order to crush a can just by condensing the water vapor inside the can. This lab write-up is due Friday.

Chem 9- We focused on Dalton's Laws of Partial Pressures. These two inter-related laws are as follows:
The total pressure of a mixture of gases must be equal to the sum of the partial pressures of the gases in the mixture. That is pretty much an obvious statement but it is essential in understanding the next law: the partial pressure of each gas equals its "mole fraction" times the total pressure. The "mole fraction" of gas "A" represents the fraction of all of the collisions of the gas particles that are due to gas A. Thus, if half of the gas molecules in a mixture of gases are gas A molecules, then gas A molecules cause half of the collisions that are occurring at any given time in that container. Therefore, gas A causes/accounts for half of the pressure in that mixture.
We then did several examples and permutations of Dalton's Law problems.

Bio- we reviewed the various types of asexual reproduction. We then applied our knowledge of what occurs during the various phases of mitosis and interphase to an on-line quiz that showed slides of cells in various stages of cell division. We also focused on the "diploid" chromosome number; diploid means that there are two of each type (size, traits coded for) of chromosome. For example, human body cells (all human cells except for sperm cells and egg cells) have a diploid number of 46; that is 23 PAIRS of chromosomes totalling 46 separate chromosomes. Mathematically, this diploid number is written as 2n. So, for humans, 2n = 46.
We saw that, for whitefish, 2n = 18 because each whitefish cell has 18 separate chromosomes or 9 PAIRS of chromosomes.
Here is the link to that website.
Here is a link to a good pictorial site on Mitosis

Chem 7- we reviewed some of the graphs that represent the gas laws.
We then focused on Dalton's Laws of Partial Pressures. These two inter-related laws are as follows:
The total pressure of a mixture of gases must be equal to the sum of the partial pressures of the gases in the mixture. That is pretty much an obvious statement but it is essential in understanding the next law: the partial pressure of each gas equals its "mole fraction" times the total pressure. The "mole fraction" of gas "A" represents the fraction of all of the collisions of the gas particles that are due to gas A. Thus, if half of the gas molecules in a mixture of gases are gas A molecules, then gas A molecules cause half of the collisions that are occurring at any given time in that container. Therefore, gas A causes/accounts for half of the pressure in that mixture.
We then did several examples and permutations of Dalton's Law problems.

Chem 8/9- we completed each of the graphs representing the various gas laws: Boyle's, Charles's, Gay-Lussac's, and Avogadro's. We saw that ONLY Boyle's Law shows an INVERSE relationship (HYPERBOLA) between the variables, which are pressure and volume (given unchanging temperature and "moles"/number of gas molecules. All of the other laws show a directly proportional (LINEAR) relationship, that is, as one variable increases, the other variable increases.
We then did a lab that showed one of the gas laws can be applied in order to crush a can just by condensing the water vapor inside the can. You'll receive the handout for that lab tomorrow but I'll post a copy on Blackboard anyway.

Bio- we reviewed the properties of DNA that enable it to self-replicate as long as there is a supply of nucleotides (A,T,G, and C) in the nucleus; since A only pairs with T and G only pairs with C to form the long double-helix chain shaped molecule, when the chain "unzips" to begin replication, only the SAME/identical base pairings AND sequence of base pairs can form; in other words, the DNA molecule is a TEMPLATE/PATTERN/BLUEPRINT for itself. Thus, TWO identical double-helix chain shaped molecules form.
These TWO DNA molecules are the TWO "sister" chromatids initially joined at a CENTROMERE to form one chromosome during the S phase of interphase.

We then discussed FIVE different types of ASEXUAL REPRODUCTION: this is reproduction that results in OFFSPRING that are GENETICALLY the SAME as/IDENTICAL to the parent cell OR organism.
1. Binary Fission - occurs in bacteria ( NO mitosis because there is NO nucleus, though the end result is the same: two cells with identical chromosomes)
2. Budding- in YEAST and Hydra; the UNEVEN division of cytoplasm BUT the formation of GENETICALLY IDENTICAL daughter cells.
3. Sporulation- in molds (and some plants) - the spores formed via mitosis are all genetically identical; these spores are dispersed/distributed/disseminated by wind or water and the spores will develop/germinate when conditions (moisture, nutrients, temperature) are favorable.
4. Regeneration - in MULTICELLULAR organisms such as the starfish and planaria (NOT in complex, highly cell-specialized vertebrates); a starfish or planaria can be chopped into pieces and then genetically identical and complete starfish or planaria can develop via mitotic cell division.
5. Vegetative Propagation- in PLANTS. Genetically identical plants can be bred via
-1) cutting- many plants/flowers
-2) grafting - typically fruit trees and bushes
-3) layering- typically plants with above ground vines or stems that touch the ground
of already formed plants.

Chem 7/8: we looked at the GRAPHICAL versions of each of the gas laws. We saw that all BUT ONE of the gas laws showed a LINEAR, direct proportional relationship (Charles's Law, both Avogadro's Laws, and Gay-Lussac's Law). The one law that necessarily shows an inverse relationship (because when you put PRESSURE on a gas, its volume SHRINKS/DECREASES) is Boyle's Law which shows that, as pressure goes up, volume goes down, given constant Temperature and number of molecules of gas.
We then focused on Avogadro's Law in a more colloquial way (which we then proved via the ideal gas law): given equal temperature and pressure, EQUAL VOLUMES of ANY gas or gases contain an EQUAL number of molecules; e.g. a two liter container of Helium gas and a two liter container of carbon dioxide gas at the SAME temperature and pressure will have the SAME EXACT number of molecules in their containers. This was Avogadro's great hypothesis that has been tested and supported in millions of experiments; since his statement does not EXPLAIN this phenomena, Avogadro's statement is a LAW, not a THEORY. Ultimately, Avogadro's Law can be explained by Kinetic Molecular Theory.
We also reviewed the two factors that contribute to the kinetic energy of a particle: velocity AND mass. So given the same average kinetic energies/temperatures, a heavier molecular weight gas has slower molecules than a lighter molecular weight gas.

Chem 9 - Bring in an empty, 12-ounce soda can for tomorrow's lab period. Good times.
today, we looked at the GRAPHICAL version of Boyle's and Charles's laws. We will do the other gas law graphs, tomorrow.
The one law that necessarily shows an inverse relationship (because when you put PRESSURE on a gas, its volume SHRINKS/DECREASES) is Boyle's Law which shows that, as pressure goes up, volume goes down, given constant Temperature and number of molecules of gas.
We also reviewed the two factors that contribute to the kinetic energy of a particle: velocity AND mass. So given the same average kinetic energies/temperatures, a heavier molecular weight gas has slower molecules than a lighter molecular weight gas.

The class notes for the rest of this unit are now posted on Blackboard in Course Documents. Download the notes, review the notes that we have covered so far, and PREVIEW the information that we will cover next week.

All Classes: This could be one of the most important proofs/discoveries in the history of humanity. Check out this simple article.

Bio- HW for this weekend: Outline Text Section 11.1 (that's right, Chapter ELEVEN is on DNA) and finish writing your mitosis lab; both the outline and the lab are due on Monday.
You may use these or any related sites for assistance with the lab:
http://www.microscopy.fsu.edu/micro/gallery/mitosis/mitosis.html
http://biog-101-104.bio.cornell.edu/biog101_104/tutorials/cell_division/wf_review_fs.html

Chem 7- we did some more Gas Law practice showing how to use the Combined Gas Law to solve a word problem. Practice these problems EXACTLY AS WE DID THEM IN CLASS. Do not take chances with a LESS careful method (this includes ALL methods except for the one that I showed you). The same mistakes that some of you make because you do not follow test-taking or problem-solving advice will cost you much more on this upcoming test because this test involves mostly MULTI-STEP math problems that result in many careless errors.
We then discussed the four tenets of Kinetic Molecular Theory and related them to how a gas can behave "ideally"=like an ideal gas. We will develop this further and also show you how each gas law looks GRAPHICALLY. It is extremely important to know how to GRAPH the gas laws and to see the characteristic curve or line for each law- we will do a lab on that next week.
For lab on Monday, bring in an empty 12-ounce aluminum soda can. We'll apply a gas law to the can!

Chem 8/9- we finished deriving the various gas laws and saw how they could be combined into either the "Combined Gas Law" or the "Ideal Gas Law". We then developed a fail-safe method for solving any gas law problem in the QUICKEST and MOST ERROR-PREVENTING manner. Practice all gas law problems EXACTLY AS WE DID THEM IN CLASS. Do not take chances with a LESS careful method (this includes ALL methods except for the one that I showed you). The same mistakes that some of you make because you do not follow test-taking or problem-solving advice will cost you much more on this upcoming test because this test involves mostly MULTI-STEP math problems that result in many careless errors.
We then discussed the four tenets of Kinetic Molecular Theory and related them to how a gas can behave "ideally"=like an ideal gas. We will develop this further and also show you how each gas law looks GRAPHICALLY. It is extremely important to know how to GRAPH the gas laws and to see the characteristic curve or line for each law- we will do a lab on that next week.

Bio- we discussed and drew the structure of DNA and noted the characteristics of the molecule that allows DNA to accurately replicate itself.
DNA, the principal component of chromosomes, replicates itself during the S phase of INTERphase. The double helix "unzips" as the weak attractions between complementary base pairs (A-T or C-G) are broken (with the aid of enzymes) so that TWO double helix DNA molecules can be synthesized from one.
See this in our notes, video, and PowerPoint on Blackboard.

Chem 7/8: we derived and explained in terms of:
1. Average KE (KELVIN temperature) of the molecules
2. Number of Collisions PER SECOND, collision rate, between the molecules and the container walls
3. Average Energy/average FORCE of collisions between the molecules and the container walls.

the various gas laws. These laws show the relationships between two of the following variables (P,V, T, and n) with the remaining variables held constant for a given experiment.
Check out the interactive video that we used in class today; it is linked on Blackboard.

We then practiced "test-taking skills" in solving problems for each of the gas laws. On Blackboard, I will post the answers to those handouts; check your answers and HOW you solved the problems.

Chem 9: we derived and explained in terms of:
1. Average KE (KELVIN temperature) of the molecules
2. Number of Collisions PER SECOND, collision rate, between the molecules and the container walls
3. Average Energy/average FORCE of collisions between the molecules and the container walls.

the various gas laws. These laws show the relationships between two of the following variables (P,V, T, and n) with the remaining variables held constant for a given experiment.
Check out the interactive video that we used in class today; it is linked on Blackboard.

Bio- we completed the full picture of mitosis and cell division by reviewing the specific details of each phase; we the examined the three parts of the "non"-division part of the cell cycle: interphase. We saw that these parts are G1 for growth of cell components, S for synthesis of DNA (duplication of the chromatin/chromosomes), and G2 more cell growth and for making products that induce/cause PROPHASE to begin.

We will now focus on DNA: explicitly/in detail, how the DNA can be replicated exactly so that there are two IDENTICAL "sister" chromatids that make up each chromosome. Eventually, these identical sister chromatids will become TWO individual chromosomes as the chromatids are pulled apart during anaphase.
I know that chromatin, chromosome, and chromatid are ALL annoyingly similar and they ALL CAN be the same thing, but we should know which term to use in a given phase of mitosis.

Reminder that text 8.2 outlines are due tomorrow, Thursday.

Chem 7- we began our new unit on the behavior of gases and the gas laws.
We started with the overall "Combined Gas Law" and then considered the relationships between two variables at a time.
We used Kinetic-Molecular Theory, mainly discussing collision frequency and collision force) to EXPLAIN Avogadro's Law and Charles's Law.
Note on current lab grades: I WILL allow, only for the labs already handed in, corrections for credit. The corrections must be ACCURATE, detailed, and VERY neat. Do ALL corrections in a different colored ink.

Chem 8/9- we began our new unit on the behavior of gases and the gas laws.
We started with the overall "Combined Gas Law" and then considered the relationships between two variables at a time.
We used Kinetic-Molecular Theory, mainly discussing collision frequency and collision force) to EXPLAIN Avogadro's Law and Charles's Law.
We then discussed, in detail, our Kinetics lab, which is due tomorrow (Thursday).
Note on current lab grades: I WILL allow, only for the labs already handed in, corrections for credit. The corrections must be ACCURATE, detailed, and VERY neat. Do ALL corrections in a different colored ink.

Bio- we began our fourth unit which focuses on mitosis and cytokinesis ; we will also describe and illustrate how DNA replicates before mitosis.
The videos from today's class and a PowerPoint for the next lesson are posted on Blackboard.
Here is the HW for the rest of the week:
Wednesday- Outline Text 8.2 (due Thursday- if late, half credit maximum)
Thursday- Outline Text 8.3 (due Friday- if late, half credit maximum)
Friday/Weekend- Outline Text 11.1 (due Monday, if late, half credit maximum)

Chem 7/8- we had our Kinetics, Enthalpy and Entropy unit exam;
we then finished discussing our Kinetics lab, which is due on Wednesday.
REMINDER:
for credit, ALL lab reports must:
-show clear and correct work (explanations and calculations)
- be written NEATLY in complete sentences,
- have correctly recorded MEASUREMENTS with respect to the precision of the instruments used
-have measurements with number AND unit clearly and properly written independently or when used in equations (units cannot disappear and suddenly reappear, though they may or should cancel out sometimes).
- have the correct number of significant figures in the calculations.

Chem 9-we had our Kinetics, Enthalpy and Entropy unit exam.

Bio- we had our Cells and Cellular Transport exam; I will be grading those exams today and tomorrow.
We reviewed some of our old labs and I stressed that labs must be neat, complete, and accurate. If you have ANY questions on future labs, ask me at extra help or email me BEFORE the lab is due.
We begin our new unit on Cell Division (recall that we thoroughly discussed when and why a cell must divide or die.

Chem 7- we covered the two requirements for a spontaneous reaction at any given temperature:
increasing entropy/chaos/randomness/disorder/number of ways to arrange particles
AND
decreasing enthalpy/PE (which means more STABLE, more strongly bonded products).
We focused on ways to predict and recognize increases or decreases in entropy:
solid phase has the lowest entropy; liquid or aqueous has higher entropy; gas phase has BY FAR the highest entropy of particles.
Also, given all the same phase, if the products have more "units"/moles of particles than do the reactants, there is an increase in entropy (you can arrange MORE particles in MORE ways).
Study hard (WRITE OUT lots of examples and do a lot of questions) tonight and tomorrow morning. I'll be in Room 301 for extra help (SPECIFIC questions that you have already worked on but that gave you difficulty).
I posted today's notes and the EXTENSIVE worksheet answers (Topic 3 workbook: Chemical Kinetics - that has every type of problem on it) answers to Blackboard. NOTICE that this answer sheet DEMONSTRATES proper test-taking skills of LABELING diagrams and identifying/underlining KEY TERMS in the questions! I expect to see the same on tomorrow's test.


Chem 8/9- we covered the two requirements for a spontaneous reaction at any given temperature:
increasing entropy/chaos/randomness/disorder/number of ways to arrange particles
AND
decreasing enthalpy/PE (which means more STABLE, more strongly bonded products).
We focused on ways to predict and recognize increases or decreases in entropy:
solid phase has the lowest entropy; liquid or aqueous has higher entropy; gas phase has BY FAR the highest entropy of particles.
Also, given all the same phase, if the products have more "units"/moles of particles than do the reactants, there is an increase in entropy (you can arrange MORE particles in MORE ways).
Study hard (WRITE OUT lots of examples and do a lot of questions) tonight and tomorrow morning. I'll be in Room 301 for extra help (SPECIFIC questions that you have already worked on but that gave you difficulty).
I posted today's notes and the EXTENSIVE worksheet answers (Topic 3 workbook: Chemical Kinetics - that has every type of problem on it) to Blackboard. Enjoy.

Chem- I just posted (Blackboard) Friday's notes and a copy of a practice test (with answer key) for next Tuesday's Kinetics and Enthalpy exam.
Do this practice test by Monday morning so that you can ask me questions at extra help and during our (Monday) review class. As you do this test, practice your TEST-TAKING SKILLS and apply them easily on Tuesday.

Bio- To help you review for Monday's exam, I posted, in the Course Documents section on Blackboard, a fun and interactive Jeopardy powerpoint on the Cell and Cellular Transport Unit.
Just click on the slideshow after you download the file.

Bio- we discussed and came up with examples of the "Levels of Organization" that complex, multi-cellular organisms need to survive. Without cell differentiation and levels of organization, humans could just be slabs of skin cells, the equivalent of a tissue culture, incapable of walking, talking, or thinking.
The simplest level of organization contains cells, then related cells work together to form tissues, which work together to form organs, which work together to form organ systems which make up the entire complex organism!
Speaking of working together, in single-celled organisms and in EACH cell of a multi-cellular organism, ORGANELLES must work together to keep the cell alive.
This weekend, think of ways that various organelles work together, that is, the life process of one organelle (e.g. mitochondria=respiration=provides cell energy via ATP) helps another organelle to perform its life process (cell membrane=excretion via active transport requires ATP from the mitochondria!!).

We looked at some cool videos involving active transport: the paramecium uses its contractile vacuole to pump water from its inside (lower water concentration) to the outside freshwater (higher water concentration) which requires ATP (for the contraction of the vacuole).

Look at your notes and previous blog entries (here) for the answers to each of the unit objective questions.
Good luck on the test on Monday!

Chem 7/8- we reviewed the factors that influence the rate of a chemical reaction (number of effective collisions per second) including the fundamental factor for each specific reaction: the nature (strength of the bonds) of the reactants. The stronger the bonds within the reactant particles, the slower the reaction at room temperature because so much energy is required to break the bonds (i.e. HIGH activation energy) that there are very few effective collisions per second at room temperature.
We then discussed the two factors that determine whether a given reaction is SPONTANEOUS (occurs without a constant supply of energy from a battery or electrical outlet or separate burner). The two factors are
1. the potential energy of the products relative to that of the reactants (nature favors LOWER PE, MORE STABILITY, STRONGER BONDS) and
2. the ENTROPY (chaos, disorder, randomness, number of ways that the particles can be arranged) of the products relative to that of the reactants. Nature favors HIGHER entropy, more chaos and disorder! Statistically and by definition, it is just more PROBABLE and natural for things to be arranged in MORE WAYS than fewer ways.

Chem 9- we reviewed the factors that influence the rate of a chemical reaction (number of effective collisions per second). We focused on the surface area of solids (and liquid or aqueous solutions too) showing that DECREASING particle size/INCREASING surface area EXPOSES more particles for collision with the other reactants thus increasing the number of collisions per second.
The fundamental factor that determines the basic rate for each specific reaction at "normal" or room temperature is: the "nature" (strength of the bonds) of the reactants. This factor cannot be "added" or taken away from a given reaction. The stronger the bonds within the reactant particles, the slower the reaction at room temperature because so much energy is required to break the bonds (i.e. HIGH activation energy) that there are very few effective collisions per second at room temperature.

Bio- we did the NY Bio Regents required lab on diffusion of glucose and iodine (and lack of diffusion of starch). Our results were as expected for a "cell" membrane (the dialysis tubing) that is permeable to RELATIVELY small molecules such as glucose (though a glucose molecule is about 10 x larger than a water molecule) and iodine ( an iodine molecule is about 4 x larger than a water molecule). We observed that starch molecules, which are polymers of glucose i.e. they are polysaccharides, are too large (hundreds of times larger than water molecules) to go through the selectively permeable "cell" membrane.

We observed that the glucose did not rapidly diffuse through the cell membrane but we still observed, via the use of heated Benedict's solution, that some glucose did diffuse through the membrane and into the outer solution; the glucose and Benedict's solution, when heated, turned brick red.

Tomorrow, we will finish our unit on the cells and cellular transport (active and passive types)
and review for MONDAY'S exam (also, text 7.3 outline is due on Monday).
Test 1 (Scientific Method and Biology Lab Tools test) corrections are due on Friday.

Chem 7- we explained the other two factors that affect the rate of chemical reactions (i.e. the rate of EFFECTIVE collisions between reactant particles). The factors are:

3. SURFACE AREA (for solids, liquids, or aqueous solutions)- by "CHOPPING UP" or SPREADING OUT the reactant samples (i.e. INCREASING the SURFACE AREA of the reactants), more and more reactant particles are exposed/available for COLLISIONS. So the total number of collisions per second increases, which increases the total NUMBER of EFFECTIVE collisions per second.
Nothing happens to the FRACTION of molecules that have proper orientation and nothing happens to the FRACTION of molecules that have sufficient KE for an effective collision BUT, since the total number of collisions per second is increasing, so will the reaction rate!

4. CATALYST- a catalyst is the ONLY factor that affects the FRACTION of molecules that have proper geometric ORIENTATION/POSITION for an effective collision. Furthermore, catalysts TEMPORARILY bind the reactant particles in such a way that their bonds are WEAKENED so that LESS (activation!) ENERGY is required for an EFFECTIVE collision. So, WITHOUT SPEEDING UP THE PARTICLES or changing the sample temperature, a catalyst can still increase a reaction rate by INCREASING the FRACTION of particles that have proper orientation for an EFFECTIVE collision AND ALSO lowering the energy REQUIRED for an EFFECTIVE collision. Thus, even at the same temperature, a greater fraction of particles will have SUFFICIENT KE for bond breakage since the catalyst "strained/pre-weakened" the bonds that need to be broken for an effective collision.
Recall, a catalyst is like a big, brawny bouncer that almost breaks a person's arm; if someone else comes along and merely taps (a low energy collision) the arm , the arm (bonds) will break.

Chem 8/9-
To have an EFFECTIVE collision, particles must collide with SUFFICIENT kinetic energy for bond breakage (the minimum quantity of energy for bond breakage is the reaction's ACTIVATION ENERGY!) AND ALSO the particles must collide with the proper geometric spatial orientation (so that the "correct" bonds break to form the desired products).
We discussed TWO of the FOUR factors that will AFFECT the number of effective collisions that occur per second (the REACTION RATE, literally):
Temperature and Concentration!
Increasing temperature will increase the average kinetic energy of the particles so the particles will naturally collide more frequently (less time between collisions since the particles sped up).
ALSO, increasing the temperature (average KE) will increase the FRACTION of particles that have SUFFICIENT kinetic energy for an effective collision (e.g. from 1/20 to 1/3). Therefore, the number of effective collisions per second (the reaction rate) increases.
However, temperature has no EFFECT on the FRACTION of molecules that are colliding with proper orientation so that fraction remains the same (e.g. one-fourth before, one-fourth after); the other factor, though, is more than enough to increase the reaction rate.
Decreasing temperature has the opposite effect of what was described above, naturally.

Increasing concentration means that there are MORE PARTICLES per mL than before! Therefore, there will be MORE collisions between particles every second.
Even though increasing concentration has NO EFFECT on the SPEED/KINETIC ENERGY of the particles and NO EFFECT on the fraction of particles with proper orientation, the fact that there are more collisions per second (e.g. from 5 collisions per second to 1000 collisions per second) will lead more EFFECTIVE collisions per second.
Decreasing concentration has the opposite effect of what was described above.

We mentioned the other two factors that can be used to increase or decrease a reaction rate:
surface area (for solids, liquids, or aq) and catalysts. We will discuss those more, tomorrow.

We then did our Kinetics Lab in which we investigated the influence of changing concentration on the rate of a reaction ("the iodine clock reaction"). We also looked at the effect of changing temperature on the rate of a reaction. We will discuss our results on Monday.

Bio- we reviewed osmosis of water from hypotonic (little salt, mostly water) solutions TO hypertonic (very salty, less water) solutions (on a test, ALWAYS LABEL which region is hypotonic and which region is hypertonic because there is ALWAYS a NET flow of water from hypotonic TO hypertonic regions (just draw an arrow and you will always get these questions right)!
We discussed the TWO types of PASSIVE TRANSPORT: SIMPLE DIFFUSION (if the substance is water, OSMOSIS) and, for molecules (e.g. glucose) that require a special transport protein channel BUT no use of energy from ATP, FACILITATED DIFFUSION (the transport protein FACILITATES, makes easier, the transport of the molecule or ion DOWN the concentration gradient.
We discussed Active Transport, which requires ENERGY via the breakdown of ATP-the main energy molecule of ALL organisms. Active Transport is the NET movement of a substance UP A CONCENTRATION GRADIENT. That is, net movement of the substance from a region of LOWER concentration TO a region of HIGHER concentration.

We then began a discussion of cell specialization, which is characteristic of complex, multi-cellular organisms. That is, as multi-cellular organisms develop, cells differentiate and each different cell type performs a different task. For example, human red blood cells are designed to transport oxygen to other cells in the body where as human nerve cells transmit electrochemical impulses throughout the body (in response to stimuli).
A paramecium consists of a single cell and thus performs all of its required life functions via its organelles within the cell.

Tomorrow, we will discuss "levels of organization" in multi-cellular organisms.
We will also do the NY State Regents required osmosis and chemical indicator lab. Be ready for lab as soon as the bell rings!

Chem 7/8- we did a quantitative problem involving Table I, potential energy diagrams, and calculations for a given quantity of reactant or product in the thermochemical equation.
Keep doing problems like that in the hw packet!
I will give you a comprehensive handout on those problems, tomorrow.
We then began kinetics, the study of reaction rates and the mechanisms of reactions.
We learned that chemical reactions are actually EFFECTIVE COLLISIONS between reactant particles.
To have an EFFECTIVE collision, particles must collide with SUFFICIENT kinetic energy for bond breakage (the minimum quantity of energy for bond breakage is the reaction's ACTIVATION ENERGY!) AND ALSO the particles must collide with the proper geometric spatial orientation (so that the "correct" bonds break to form the desired products).
We demonstrated TWO of the FOUR factors that will AFFECT the number of effective collisions that occur per second (the REACTION RATE, literally):
Temperature and Concentration!
Increasing temperature will increase the average kinetic energy of the particles so the particles will naturally collide more frequently (less time between collisions since the particles sped up).
ALSO, increasing the temperature (average KE) will increase the FRACTION of particles that have SUFFICIENT kinetic energy for an effective collision (e.g. from 1/20 to 1/3). Therefore, the number of effective collisions per second (the reaction rate) increases.
However, temperature has no EFFECT on the FRACTION of molecules that are colliding with proper orientation so that fraction remains the same (e.g. one-fourth before, one-fourth after); the other factor, though, is more than enough to increase the reaction rate.
Decreasing temperature has the opposite effect of what was described above, naturally.

Increasing concentration means that there are MORE PARTICLES per mL than before! Therefore, there will be MORE collisions between particles every second.
Even though increasing concentration has NO EFFECT on the SPEED/KINETIC ENERGY of the particles and NO EFFECT on the fraction of particles with proper orientation, the fact that there are more collisions per second (e.g. from 5 collisions per second to 1000 collisions per second) will lead more EFFECTIVE collisions per second.
Decreasing concentration has the opposite effect of what was described above.

We then discussed the heat of solution of NaOH lab. We changed "moles" to grams, for our write-up. We also acknowledged that, even though we are using the specific heat of water, we really should use the value of the specific heat of the solution but we assume that those two values are almost the same for our degree of precision.

Chem 9- we did a quantitative problem involving Table I, potential energy diagrams, and calculations for a given quantity of reactant or product in the thermochemical equation.
Keep doing problems like that in the hw packet!
I will give you a comprehensive handout on those problems, tomorrow.
We then began kinetics, the study of reaction rates and the mechanisms of reactions.
We learned that chemical reactions are actually EFFECTIVE COLLISIONS between reactant particles.
To have an EFFECTIVE collision, particles must collide with SUFFICIENT kinetic energy for bond breakage (the minimum quantity of energy for bond breakage is the reaction's ACTIVATION ENERGY!) AND ALSO the particles must collide with the proper geometric spatial orientation (so that the "correct" bonds break to form the desired products).
Tomorrow, we will discuss and demonstrate the four factors that can affect the number of effective collisions per second between reactant particles i.e. the reaction rate.

Bio- Good news, good times: Thanks to Chem teacher extraordinaire, Mrs. Rinaudo, I now have your grades linked on Blackboard. Click on the newly created "Grades" section, enter your Last Name and your cAsE sEnsitIve password and you can view your currently graded tests/assignments.
Today, we explained, step-by-step, the process of diffusion and why diffusion MUST occur as particles RANDOMLY moving in all directions will naturally spread out (diffuse) from a region of higher concentration to a region of lower concentration.
We then carefully went through the diffusion of WATER, which is OSMOSIS (water gets its own special term for diffusion!). The trick is to see that, the MORE things (solutes/salts/molecules) that are dissolved in water, the LESS concentrated the WATER is. The "most" concentrated water is pure, 100%, water. Water will diffuse (undergo osmosis) always from a region of higher water concentration to a region of lower water concentration.
Check out this video of osmosis of water from inside an Elodea plant cell TO a hypertonic
(= very salty!= LOWER water concentration) salt solution.
http://www.linkpublishing.com/Videos/transport/elodea_hyper.wmv

Check out this video of osmosis of water from PURE, distilled water (100% water = higher concentration) outside of an Elodea plant cell TO inside the Elodea plant cell (where there is a LESS THAN 100% water concentration).
http://www.linkpublishing.com/Videos/transport/elodea_hypo.wmv

Here's red BLOOD cells bursting as they are put in distilled, 100% water so that the water diffuses (OSMOSIS) into the red blood cells (about 90% water, 10% solutes).
http://www.linkpublishing.com/Videos/transport/blood_hypo.wmv

Chem 7- we worked Table I into our potential energy/Enthalpy diagrams of chemical reactions and physical changes (dissolving) noting all of the relevant quantities: PE products, PE reactants, delta H = PEp - PEr (pepper!!!), PE activaTED complex,
Eact (activaTION energy)forward reaction, and Eact reverse reaction.
We also did some proportion calculation regarding energy change if more or fewer UNITS (moles) of products are formed than the quantities in the given thermochemical equation.
In the Topic 3 hw packet, you should now be able to answer all of the questions except for the ones on the back of the last page.
Tomorrow, we will discuss/explain the FOUR factors that can affect the rates of chemical reactions and how they do so.

Chem 8/9- we worked Table I into our potential energy/Enthalpy diagrams of chemical reactions and physical changes (dissolving) noting all of the relevant quantities: PE products, PE reactants, delta H = PEp - PEr (pepper!!!), PE activaTED complex,
Eact (activaTION energy)forward reaction, and Eact reverse reaction.
We also did some proportion calculation regarding energy change if more or fewer UNITS (moles) of products are formed than the quantities in the given thermochemical equation.
Tomorrow, we will discuss/explain the FOUR factors that can affect the rates of chemical reactions and how they do so.
In the Topic 3 hw packet, you should now be able to answer all of the questions except for the ones on the back of the last page.

We did a lab in which we measured the delta H of dissolving of NaOH (sodium hydroxide, the base that is used in drain cleaner and soap-making), which is also called the heat of "solution".
We are (again) ignoring any energy absorption by the styrofoam itself; we can do this because styrofoam is a good insulator and does not have a noticeable temperature change during these experiments. So, there is a built-in source of error in our procedure and subsequent calculations( which is the case in ANY experiment though some have more built-in error and some have less).

Bio- for HW, outline text section 7.2; I will collect the outline on Wednesday.
we reviewed the organelles and their functions; we then compared and contrasted plant and animal cells by noting the organelles common to both cells and the organelles that are unique to each type of cell.
We then began a discussion of the main/crucial processes to understand about materials that are transported into or out of cells:
passive transport (diffusion) and Active TransPort (requires energy/use of ATP).
I showed a video of a substance naturally/spontaneously diffusing (moving from a region in which it is highly concentrated to a region in which its concentration is lower). I'll post the video on Blackboard in the Course Documents section.
Tomorrow, we will do a demo and a lab involving diffusion of water (called OSMOSIS, which is LITERALLY the diffusion of water).

Chem 7/8- we looked at some telltale signs of a chemical change/reaction:
gas formation, precipitation/insoluble solid formation, color change, and fire/light emission accompanied by heat release or, oppositely, energy absorption. The last two signs are not definitive indications of a chemical change because they can also be signs of a mere physical change.
We labeled all of the relevant and important arrows in an enthalpy diagram with and without a catalyst. We also did some quantitative calculations with the PE values from the diagram of the given reaction.
I will show you how to use Table I, tomorrow.

We then did a lab in which we will measure the "heat of solution" which is the energy change per specific amount of substance dissolved. This is a PHYSICAL process because the sodium hydroxide merely dissolves in but does not react with the water.
I will discuss the calculations with you all on Wednesday.

Test corrections are due on Wednesday.

Chem 9- we looked at some telltale signs of a chemical change/reaction:
gas formation, precipitation/insoluble solid formation, color change, and fire/light emission accompanied by heat release or, oppositely, energy absorption. The last two signs are not definitive indications of a chemical change because they can also be signs of a mere physical change.
We labeled some of the relevant and important arrows in an enthalpy diagram. We will complete both the exothermic and endothermic PE/enthalpy curves.
I will also show you how to use Table I, tomorrow.

We then did a lab in which we will measure the "heat of solution" which is the energy change per specific amount of substance dissolved. This is a PHYSICAL process because the sodium hydroxide merely dissolves in but does not react with the water.
I will discuss the calculations with you all on Wednesday.

Test corrections are due on Wednesday.

Bio- we analyzed the cell membrane by looking at its composition (phospho-lipid bi-layer with embedded transport, receptor, recognition, and adhesion proteins that comprise a "fluid mosaic"), structure, and main functions (regulation and transport). We then focused on the nucleus (only found in eukaryotic cells), its structure, and function. We briefly discussed all other organelles, which we will revisit on Monday: mitochondria, rough ER, smooth ER, Golgi Bodies, ribosomes, microfilaments/tubules, centrioles, vacuoles, chloroplasts (only in plants and green algae), and lysosomes.
We reviewed some of our Biochemistry exam and I showed you how to do test corrections so that you would LEARN from your mistakes in such a way that you would understand the material that you needed to know before the exam. Corrections can be tedious and painstaking; they are supposed to be. Its part of learning something that leaves a long-term impression on you.
Your corrections must THOROUGHLY and CLEARLY EXPLAIN (how and why) each question and its correct answer. You should include drawings, diagrams, and/or illustrations in most of your corrections. Then, you should realize that, as you take your next test, these exact requirements your for corrections can earn you a lot more points as you apply them directly on your next exam; this way, you will be forced to reason your answers and identify the key terms in each question so that you do not choose a true BUT irrelevant answer.

In case you need extra help on Monday morning, I will allow one more day for the Biochem corrections hw; I will collect that hw on Tuesday.
Your password protected grades are now on Blackboard. I do not have the grade for the labs posted yet, though.
Parents, check the grades frequently; thank you.

Chem 7- we did several examples of writing endothermic and exothermic equations in both formats (energy term in the equation and energy term with the appropriate sign after the semicolon). We also balanced the equations and drew Dalton models of the molecules to SEE that the equations were balanced. Don't forget that for the next test!
We then drew and explained what happens, in terms of potential energy/enthalpy, throughout an exothermic or an endothermic reaction. Knowing how to properly label these two different diagrams is a crucial skill in chem. You MUST know the PE of the reactants, the PE of the products, the PE of the "activatED complex", the "heat of reaction" or "delta H", the Activation Energy (Eact), and, as you will see, the effect on PE of adding a catalyst.
We will also do some quantitative calculations with these diagrams.
After that, we will learn and reason through the FIVE factors that can affect or determine the rate of a chemical reaction.I did not have time to collect the labs that were due so I will do so at the beginning of class on Monday.
Your password protected grades are now on Blackboard. I do not have the grade for the labs posted yet, though.
Chem 8/9 -we did several examples of writing endothermic and exothermic equations in both formats (energy term in the equation and energy term with the appropriate sign after the semicolon). We also balanced the equations and drew Dalton models of the molecules to SEE that the equations were balanced. Don't forget that for the next test!
We then drew and explained what happens, in terms of potential energy/enthalpy, throughout an exothermic or an endothermic reaction. Knowing how to properly label these two different diagrams is a crucial skill in chem. You MUST know the PE of the reactants, the PE of the products, the PE of the "activatED complex", the "heat of reaction" or "delta H", the Activation Energy (Eact), and, as you will see, the effect on PE of adding a catalyst.
We will also do some quantitative calculations with these diagrams.
After that, we will learn and reason through the FIVE factors that can affect or determine the rate of a chemical reaction.
We then did a lab in which we identified an exothermic CHEMICAL change/reaction and an endothermic chemical change/reaction. I'll give you the lab sheet for that on Monday or Tuesday. I did not have time to collect the labs that were due today so I will do so at the beginning of class on Monday.
Your password protected grades are now on Blackboard. I do not have the grade for the labs posted yet, though.

Bio- we focused on the underlying reason for cell division (cytokinesis): the surface area to volume ratio of the cell. As a cell grows, surface area increases at a slower rate than volume which is why the surface area to volume ration decreases and the cell is compelled to either divide or die.
The notes and PowerPoints for this week are on Blackboard.

HW- Outline Text Section 7.1, due Friday.

Bring in your Biochem tests for Friday. We will go over TEST-TAKING skills, which continue to be completely ignored by those of you who did not do well on the test. If you want to improve, you will consistently follow the invaluable test-taking advice that I demonstrate to you.

Reminder: as soon as you reach your desk in class, take out your notebook and either copy what is on the board or be prepared to immediately take notes as soon as attendance is taken.

Chem 7/8- Here is a link to yesterday's Nobel Prize winning chemist!
We began our new unit on Chemical Reactions and Kinetics. We noted where to place REACTANTS (before the arrow) and PRODUCTS (after the arrow). We emphasized balancing chemical equations in order to respect the Law of Conservation of Mass in a chemical reaction. We also learned two ways to represent either an endothermic or an exothermic thermochemical equation/reaction.
The notes and worksheet are on Blackboard.
Heat of Fusion and Phase Change labs are due Friday, Oct. 12 !
We then did a lab in which we identified an exothermic CHEMICAL change/reaction and an endothermic chemical change/reaction.

Chem 9- Here is a link to yesterday's Nobel Prize winning chemist!
We began our new unit on Chemical Reactions and Kinetics. We noted where to place REACTANTS (before the arrow) and PRODUCTS (after the arrow). We emphasized balancing chemical equations in order to respect the Law of Conservation of Mass in a chemical reaction. We also learned two ways to represent either an endothermic or an exothermic thermochemical equation/reaction.
The notes and worksheet are on Blackboard.
Heat of Fusion and Phase Change labs are due Friday, Oct. 12 !

Bio- we continued our discussion about cells and reviewed some of the key differences between prokaryotic (no nucleus) and eukaryotic (true nucleus) cells. We questioned why a growing cell must eventually divide or else die, focusing on two competing factors:
as a cell grows, its surface area through which nutrients are absorbed INCREASES (a good thing) BUT, as a cell grows, its VOLUME also increases, which may make it very difficult for the nutrients to get to where they need to go in the cell in sufficient time to keep the cell alive!
Which factor is more important as the cell reaches its critical peak size?
Answer and explanation, tomorrow.
By the way, here is a link to the site that shows a cell (of Paramecium bursaria, the green paramecium) that is so unusually large, that it is visible to the naked eye.


We conducted a lab investigating the effect of pH on the activity of the enzyme, CATALASE. You produce this enzyme in your own cells so that any hydrogen peroxide that forms via metabolic activities can be quickly catalyzed/converted/decomposed into harmless water and oxygen gas.
I noticed that all of you made observations that are consistent with what we know about enzymes, their shapes, and their resulting functions/degrees of activity.

Chem 7- we had our unit exam on Energy and Phase Changes.
Good to see that some of you took the test-taking advice that can only help you maximize your score. I want to see more people help themselves by consistently applying these techniques.
Your phase change and heat of fusion labs are due Friday and will be placed into your lab folders then; make sure that the labs are neat and complete! Check Blackboard for the map/outline and heating curve data for the labs.
We begin our new unit on Kinetics ( a.k.a. WHY things blow up), tomorrow.

Chem 8/9- we had our unit exam on Energy and Phase Changes.
Good to see that some of you took the test-taking advice that can only help you maximize your score. I want to see more people help themselves by consistently applying these techniques.
We then discussed/explained our two energy and phase change labs. These labs are due Friday and will be placed into your lab folders then; make sure that the labs are neat and complete!
Check Blackboard for the map/outline and heating curve data for the labs.
We begin our new unit on Kinetics ( a.k.a. WHY things blow up), tomorrow.

I hope that you heed this test-taking advice that has helped thousands of my past students who let me know, even after they go to college, how valuable and practical these tips are.

As you prepare for a test by doing problems and WRITING out and/or DRAWING pictures of explanations, do so exactly as you will be writing on the test; that is, neatly and carefully showing all formulas, units, and calculations with attention to sig figs or labeling all parts of a diagram along with the molecular/particle picture that accompanies the diagram (see notes for examples).

After doing three to five of each type of problem in this unit, the process should become second nature and you will not only get an accurate (true) answer, but also you will reach the answer efficiently because you will see that most of these problems are practically identical.

The key test-taking skill that is consistently ignored by most students (costing them dozens or even hundreds of points per quarter!) involves identifying, labeling, and underlining/circling/highlighting the key terms or data in a question. Once you identify those key terms, you can actually think about what the answer requires. Without knowing what the question asks, you probably will choose a familiar AND true but irrelevant answer.
The data in a quantitative question will always dictate what formula to use so it is mandatory to label the types of data in each question with their respective units. You will find that, in any quantitative question that only one piece of information is missing from the relevant equation and that piece of info is actually what you are solving for!
For example, if the question says that 2458 J of energy were extracted from 654 grams of water at 35.0 degrees C, then what will the final temperature of the water be, then you can see that the energy , q, is given, the mass, m, is given, the substance, water, is given, meaning that you can use the specific heat of liquid water, c, and the initial temperature, Ti, is given.
You are asked for the final temperature, Tf. The only equation that we know of that has those variables is q = mc deltaT.
So, just rearrange , and solve for delta T, which equals q/mc.
Then set delta T = Tf - Ti and solve for Tf.
Done and done! When you take time and care reading and annotating a question, you prevent yourself from making knee-jerk careless mistakes and you also take control of the given problem by identifying what you have and the one thing that you need.

For any endothermic or exothermic problem, DO YOURSELF A BIG FAVOR and DRAW out the situation! If you have a salt-dissolving scenario and the test-tube gets hotter as the salt dissolves, DRAW the arrows of energy going OUT OF the solution TO the glass test-tube and surroundings PROVING to yourself that this is an EXO (out of!) thermic dissolving process (i.e. the surroundings got hotter) typical of a chemical heat pack.
Same deal for melting an ice cube: DRAW the energy arrows going ENDO/into! the ice cube FROM the surroundings in order to melt the ice cube. Since the surroundings LOSE energy, the surroundings will cool, which DOES happen every time that ice melts!

So, abide by these simple yet painstaking tips and watch your test performance improve.
Good luck tomorrow (you won't need it if you have been preparing but I wish it to you just the same).

Bio- we began our new unit: Cells and Cell Processes.
The videos from today and the notes can be downloaded from Blackboard in the "Class Documents" section. Check them out.
Tomorrow, we will collate, collect, and review our lab writeups as well as do another lab.
I will also have your Biochem Unit test grades. Also tomorrow, you will give me a password so that you and your parents can keep track of your grades via Blackboard.

Chem 7/8: we analyzed and dissected Table H: Vapor Pressure (of four different substances) vs. Temperature and covered every permutation that can be asked about that.
We then did a calorimetry problem in which we calculated energy absorbed by the water in the calorimeter; then, we were able to determine the specific heat of an unknown metal.
We also looked at every topic that is on tomorrow's test-
the notes from that are now on Blackboard in the Cicale's Assignments section.
Also, the class "Phase Change" lab data is posted, in case your experimental data was inadequate.

Chem 9- we analyzed and dissected Table H: Vapor Pressure (of four different substances) vs. Temperature and covered every permutation that can be asked about that.
We had time to start a calorimetry problem in which we calculated energy absorbed by the water in the calorimeter; then, we were able to determine the specific heat of an unknown metal. The solution to that is posted in the review sheet/notes on Blackboard in the Cicale's Assignments section.

Hi Chemsters (what?),
A copy of the practice test for next Wednesday's "Energy and Phase Changes" exam is posted on Blackboard in the Cicale's Assignments section.
Also, the answers to the Topic 2 HW packet are posted in the "Homework" section.
Be sure to prep over this three-day weekend (at the very least, study on Sunday and Monday) so that, if you have any questions for me on Tuesday and/or Wednesday, I can help to clarify things for you and then give you some extra examples for reinforcement.
I will give extra help before school on Tuesday and Wednesday morning at about 8AM in Room 301. Come prepared with specific questions that you considered difficult.
Be there.
Mahalo.

Bio- we had our Biochemistry unit exam today. Most of you seemed comfortable with today's test. Some of you were too comfortable: if you finish a test early in my class, do NOT sit at your desk doing NOTHING; ALWAYS use the full time allotted to check and re-check your work and to EDIT and embellish (make better) your written answers; you should ALWAYS provide a labelled sketch or diagram as part of any description or explanation- that will improve your chances of getting full credit on a written response and it should occupy any remaining time for your exam.

No good test-taker takes a chance of doing nothing during a test especially since tests are the main mode of measurement of your knowledge. Any intelligent person can make an error (a misread question or a mis-marked answer); your job is to ASSUME that you made a careless error on your test and then to FIND that error as you carefully check your work. If you do not find any errors after repeated checks (time permitting), then you at least have the knowledge that you tried your very best and that you probably got a good or great score.

This advice applies to all tests in my class. Please take them very seriously and go all out on each exam; as a result, you will, by definition, become a better student and a better test-taker.

We spent our lab period working on our microscope and slide preparation skills. It was great to see that some of you were able to detect live organisms in the pond water slides that you prepared. It looked like some of them were fighting for survival!
On Tuesday, we will tidy up our labs and organize our lab folders as well as begin our new unit on "CELLS".
Have a great Homecoming weekend!

Chem 7- in our brief little period, we did complete our discussion of the cooling curve ( energy extracted/out/exothermic) of a substance noting all energy changes for each of the 5 segments of the "curve". We also applied a heat of "fusion" equation to the freezing of water (we just had to apply a negative sign because we were doing the OPPOSITE of fusion/melting).
We then began to discuss the source of a liquid's VAPOR PRESSURE (due to the fraction of molecules at a given temperature that have SUFFICIENT kinetic energy to OVERCOME their attractions to their neighboring molecules and thus ESCAPE into the GAS phase) and relate that vapor pressure to "BOILING".
The STRICT definition of boiling is when a substance's VAPOR PRESSURE is EQUAL to the ATMOSPHERIC or EXTERNAL pressure on the substance. The boiling POINT is the TEMPERATURE at which a substance boils.

We SAW that water COULD boil at room temperature (298K or 25 C) if we could LOWER the external pressure on the water from about 1 atmosphere to about .010 atmosphere via a vacuum pump. The vapor pressure of water at room temp is naturally about .010 atmosphere
so, as soon as we changed the surrounding pressure to equal .010 atm, the water started to BOIL!

The NORMAL boiling point will be the temperature at which a substance has a VAPOR PRESSURE of 1.00 atmosphere/ 101.3 kiloPascals of pressure.
So, for example, a 100 C or 373 K, the NORMAL boiling point of water, water has a VAPOR pressure of 1.00 atmosphere= 101.3 kiloPascals of pressure.
Ethanol-alcohol reaches a (normal) vapor pressure of 1.00 atmosphere at a mere 78 C or 351 K because not as much energy is required to get ALL of its molecules into the vapor phase. This is because ethanol molecules are not as strongly attracted to each other as water molecules are attracted to other water molecules. In fact, the stronger the intermolecular attraction of a given substance, the MORE energy is needed to reach a vapor pressure of 1.00 atm, thus the HIGHER the boiling point.
Of course, we will draw and discuss this more on Tuesday!
Have a great Homecoming weekend!

Chem 8/9: we finished our discussion of the cooling curve ( energy extracted/out/exothermic) of a substance noting all energy changes for each of the 5 segments of the "curve". We also applied a heat of "fusion" equation to the freezing of water (we just had to apply a negative sign because we were doing the OPPOSITE of fusion/melting).
We then began to discuss the source of a liquid's VAPOR PRESSURE (due to the fraction of molecules at a given temperature that have SUFFICIENT kinetic energy to OVERCOME their attractions to their neighboring molecules and thus ESCAPE into the GAS phase) and relate that vapor pressure to "BOILING".
The STRICT definition of boiling is when a substance's VAPOR PRESSURE is EQUAL to the ATMOSPHERIC or EXTERNAL pressure on the substance. The boiling POINT is the TEMPERATURE at which a substance boils.

We SAW that water COULD boil at room temperature (298K or 25 C) if we could LOWER the external pressure on the water from about 1 atmosphere to about .010 atmosphere via a vacuum pump. The vapor pressure of water at room temp is naturally about .010 atmosphere
so, as soon as we changed the surrounding pressure to equal .010 atm, the water started to BOIL!
The NORMAL boiling point will be the temperature at which a substance has a VAPOR PRESSURE of 1.00 atmosphere/ 101.3 kiloPascals of pressure.
So, for example, a 100 C or 373 K, the NORMAL boiling point of water, water has a VAPOR pressure of 1.00 atmosphere= 101.3 kiloPascals of pressure.
Ethanol-alcohol reaches a (normal) vapor pressure of 1.00 atmosphere at a mere 78 C or 351 K because not as much energy is required to get ALL of its molecules into the vapor phase. This is because ethanol molecules are not as strongly attracted to each other as water molecules are attracted to other water molecules. In fact, the stronger the intermolecular attraction of a given substance, the MORE energy is needed to reach a vapor pressure of 1.00 atm, thus the HIGHER the boiling point.
Of course, we will draw and discuss this more on Tuesday!

We performed the procedure for determining the heat of fusion (delta H fus) of water by melting a quantity of ice in warm water. Depending on how much ice melted and how much energy was absorbed by the ice (which is theoretically the amount of energy that was transferred FROM the warmer water TO the colder ice), we have the number of Joules of energy per number of grams of ice melted which IS the heat of fusion! We will discuss and debate this on Tuesday.

Have a great Homecoming weekend!

Friday is pep rally day so we have shortened, 33-minute periods. To accommodate this abbreviation, the Bio department constructed a shorter test: 25 multiple-choice questions followed by 2 "short answer"/constructed response questions.
Even so, be prepared to work quickly YET carefully. Strictly apply the test-taking skills reviewed in class today:
The SECOND AFTER the test begins, quickly jot down anything that you memorized (or wrote down but put away) in short term memory (EVEN seconds before the test!) directly on the test paper. This way, you have a quick and LEGAL cheatsheet to which you can refer for the whole test! In the past, SO MANY of my students have effectively applied that simple tip.
1. Carefully read each question while circling, underlining, highlighting the KEY words or data in each question;
2. Let the key words guide your thinking so that you can PREDICT an answer, which you can quickly jot down; to help you predict an answer, it can be very helpful to do a simple DRAWING, SKETCH of a graph, DIAGRAM, or TABLE;
3. SCAN the answers to look for a match to your predicted answer;
4. If you see a match, just circle that choice! If you do not see a match, ELIMINATE answers that cannot be correct and get the right answer to that specific question via elimination. If two or more answers remain, ONLY one of them can be right, so re-read the question and plug the answers in to the question to help clarify which one is correct.

If a question is too difficult or unfamiliar, SKIP IT, initially, and then come back to it if there is time remaining. Each multiple-choice questions are worth the same number or points so do not have one question take up so much time that you run out of time for other questions that you can answer.

I will post the answers to the practice tests that are on Blackboard in the "Class Documents" section.
Good luck tomorrow.

Chem 7/8- we performed the experimental procedure to determine the "heat of fusion/melting" of water. As is the case with all experimental procedures, there is BUILT-IN "experimental error", which REALLY means built-in "IMPERFECTIONS' in the experiment, even if YOU follow the procedure PERFECTLY. We discussed some of these imperfections that are unavoidable in this experimental design.
We did a sample heat of fusion calculation to use as a template for the lab write-up.
We also discussed that a NEGATIVE sign in any of these energy equations indicates that energy is being LOST/RELEASED/LIBERATED by/from the substance.

Chem 9- we looked at the animation (posted on Blackboard in the "Cicale's Assignments" section) that showed several things: the molecular level view of the phases and phase changes of a substance, the energy required for or released during those phase changes, and the heating curve that accompanies the aforementioned phenomena.

Glad to meet you last night! It's always interesting for me as a Biology and Chemistry teacher to see the genetic and/or personality connection between parents and their children.
I just want to impress upon you my willingness and availability to work with you to ensure the success of your children/my students. Of course, the third part of that "equation" for success is the student and, fortunately, the vast majority of my past students were in sync with me and their parents in working hard towards understanding science. Some will struggle but we can show them that most things (academic, athletic, etc.) that are worthwhile/valuable are not easy to grasp/obtain.
One thing that I didn't get to last night (time is so short for P/T night, which is why it's nice to have this blog as an addendum), was an elaboration on grading.
I was recently shown how to put my gradebook on Blackboard. I just have to link a password to each student, then I can get the password to each of you, and you can look up your daughter's/son's grade at any time throughout the quarter. Everything should be online by next late next week; if there are any unforeseen delays, I will explain via this blog.
I look forward to continuing success for my students and to establishing a great experience with you all this year and beyond.