SciHawks

AP Chem: as promised, I posted several Organic Chem files complete with a handy mnemonic reference file. Read the mnemonics file first and then try to do the worksheets.
You WILL see an organic combustion reaction in Part II of the AP exam, so you must be able to write/draw an organic formula/molecule from its name. Part I also has some organic molecules/formulas.

AP Chem- Note: I posted yet another Thermochem practice test (on Blackboard); this one has a detailed answer key ( a couple of the heat of formation values are not in your text so you will have to google them or check the answer key). I'll also post some organic chem naming tutorials because you must know/recognize all of the functional groups/types of organic molecules that you were given on the Regents cheat-chart last year; there are NO organic formulas/keys on the AP reference table so you must know each group by rote.

We corrected a few Hess Law problems by focusing on
1. ESTIMATING the correct answer (very important and most practical skill for this unit).
2. cancelling the units and understanding the overall reaction energy value is per mol of REACTION

We then did a Hess Law multi-step problem. We also discussed the meaning (and CAUSE) of the relative delta H of FORMATION values of aqueous ions. The reference value is delta Hf for H+ (aq), which is 0 kJ per mole.
We continued with another Hess Law problem: an anionic single replacement redox reaction in which we applied the enthalpies of formation of aqueous ions to calculate the overall heat/enthalpy of reaction.


Bio 6/7- we finished our discussion of the structure and function of the leaf, including the various layers and cell types. We focused on the guard cells that FORM the stoma/mouths/pores/stomates on the bottom side of the leaf. These stomates allow an easy entrance for CO2 gas from the air but they allow water vapor to escape.
We then discussed the transport of water in the xylem via capillary action, which is due to adhesion of water to the xylem walls and cohesion of water molecules to each other.
We then introduced the definition and equation for cellular respiration.We finished up our rate of photosynthesis lab, though there may have been some dead/dying Elodea that made observations difficult. We will clear that up next time.

Bio 8- we finished our discussion of the structure and function of the leaf, including the various layers and cell types. We focused on the guard cells that FORM the stoma/mouths/pores/stomates on the bottom side of the leaf. These stomates allow an easy entrance for CO2 gas from the air but they allow water vapor to escape.
We then discussed the transport of water in the xylem via capillary action, which is due to adhesion of water to the xylem walls and cohesion of water molecules to each other.
We then introduced the definition and equation for cellular respiration.

AP Chem- we looked at a rather challenging (at this time) set of reactions/descriptive chemistry, which , along with the set of reactions from last week, we will cover tomorrow.
You received thermodynamic data tables for both substances and aqueous ions (mixtures). A different standard is used for aqueous ions because they are not just a single substance (the ions are dissolved in WATER); the reference standard for change in enthalpy by which all other enthalpy changes for the dissolving of ions is measured is the H+ aqueous ion. The H+ aqueous ion is given the convenient reference value of ZERO kJ/mol.
So, use Hess's Law, as applied to aqueous ions, in the same way that you would do for any other Hess's Law problem.

Bio 6- we reviewed how and why of the factors that influence the rate of photosynthesis and drew graphs of each factor as the independent variable. We even saw that color type could be used as an independent variable that influenced photosynthetic rate.
We then began to discuss leaf structure, showing how the various layers function individually and then work together to ensure that the plant can efficiently maintain homeostasis and perform photosynthesis.

Bio 7/8- we reviewed how and why of the factors that influence the rate of photosynthesis and drew graphs of each factor as the independent variable. We even saw that color type could be used as an independent variable that influenced photosynthetic rate.
We then began to discuss leaf structure, showing how the various layers function individually and then work together to ensure that the plant can efficiently maintain homeostasis and perform photosynthesis.
We started a lab investigating the effect of (independent variable) varying light intensity on the (dependent variable) rate of photosynthesis as measured by the rate of production of oxygen bubbles, one of the products of photosynthesis. I'll have to check what went wrong with the lab; the lab usually works well and results are rapidly seen!

AP Chem- we further discussed constant pressure calorimetry, the experimental error that is built-in to these measurements (i.e. no container is a perfect insulator so some, but NOT much, energy is exchanged with the surroundings outside of the container.
We then did the long version of Hess's Law, which solely relies on the fact that Enthalpy, H, is a STATE function; that fact enables us to just algebraically manipulate several equations that ADD up to the NET equation that we desire.
But wait...
Using the STRICT definition of "heat of formation", for which we MUST know the MOST STABLE FORM and PHASE of a given substance at 298K and 1atm, we can then use the "easy/brief" version of Hess's Law, which will ALWAYS get you the same net answer as the longer version of Hess's Law.
We looked at various common elements and discussed their most stable form and phase at 298K and 1 atm and then we applied Hess's (brief) law to the "thermite reaction".

We then started a mini-lab in which we are forced to use our knowledge to assess the contents of four aqueous solutions that were "mislabeled".

Bio 6/7- we discussed the light-dependent (granum) reactions and the light-independent reactions (stroma) of photosynthesis. We then derived the various factors that must influence the rate of photosynthesis. By looking at the REACTANTS for photosynthesis (including the light energy and the enzymes involved), we figured out that altering the quantity of a given reactant MUST influence the rate of photosynthesis.

We then tested one of those factors (light intensity) in a rate of photosynthesis lab.

Bio 8 - we discussed the light-dependent (granum) reactions and the light-independent reactions (stroma) of photosynthesis. We then derived the various factors that must influence the rate of photosynthesis. By looking at the REACTANTS for photosynthesis (including the light energy and the enzymes involved), we figured out that altering the quantity of a given reactant MUST influence the rate of photosynthesis.

AP Chem: Unit 6 HW due Monday after Thanksgiving:
Read Chapter 6 and do questions 18, 22, 24, 27, 32, 34, 44, 48, 56, 58, 62, and 66.

We discussed the two types of calorimeters and the relationship between heat and internal energy in each case. For the "bomb" calorimeter, no gaseous P-V work can be done because there can be no change in volume in the sealed steel "bomb"; therefore, the heat absorbed or released is exactly the change in internal energy of the "system"/reactants.

We then did several example of calorimetry, noting whether we had to use "heat capacity" of the calorimeter or specific heat (capacity)of water or of an aqueous solution in the calculation.

We briefly discussed the longer version of Hess's Law; we will learn both versions of his law tomorrow.

Bio 6- we discussed the specific LOCATION of photosynthesis in plant cells. We saw that there are two major regions within the chloroplast: the stacks of thylakoids are called "grana", which contain the light-absorbing chlorophylls. The chlorophyll pigments absorb light energy and this energy is used in two ways: 1. some of this energy is converted to ATP, which is used to perform PHOTOLYSIS, the splitting of water into oxygen molecules and hydrogen. The oxygen diffuses from the leaf but the hydrogen is transported from the grana to be used in making glucose. 2. the rest of the light energy is used to make ATP to drive/force/cause the "light-independent" reactions that synthesize glucose from carbon dioxide and the hydrogen (from the "split" water molecules). The other cytoplasm-filled region of the chloroplast is the "stroma" where the glucose is synthesized by using the ATP that is transported from the grana as the source of energy to force the synthesis reactions.

We saw that the chlorophylls absorb violet, blue, and red light most strongly but that they do not absorb green light well. The advantage of having both chlorophylls a AND b is that, because they absorb different colors of light most strongly, more light energy can be absorbed so that more energy for photosynthesis can be supplied.

We also discussed chromatography that is used to separate and detect the various light-absorbing pigment molecules that are in a given species of plant.

Bio 7/8- we discussed the specific LOCATION of photosynthesis in plant cells. We saw that there are two major regions within the chloroplast: the stacks of thylakoids are called "grana", which contain the light-absorbing chlorophylls. The chlorophyll pigments absorb light energy and this energy is used in two ways: 1. some of this energy is converted to ATP, which is used to perform PHOTOLYSIS, the splitting of water into oxygen molecules and hydrogen. The oxygen diffuses from the leaf but the hydrogen is transported from the grana to be used in making glucose. 2. the rest of the light energy is used to make ATP to drive/force/cause the "light-independent" reactions that synthesize glucose from carbon dioxide and the hydrogen (from the "split" water molecules). The other cytoplasm-filled region of the chloroplast is the "stroma" where the glucose is synthesized by using the ATP that is transported from the grana as the source of energy to force the synthesis reactions.

We saw that the chlorophylls absorb violet, blue, and red light most strongly but that they do not absorb green light well. The advantage of having both chlorophylls a AND b is that, because they absorb different colors of light most strongly, more light energy can be absorbed so that more energy for photosynthesis can be supplied.

We also discussed chromatography that is used to separate and detect the various light-absorbing pigment molecules that are in a given species of plant.

We then did test review, going over DRAWING or GIVING SPECIFIC EXAMPLES (as we ALWAYS do in class/in the notes) in order to make your answers ACCURATE and EASIER to write.

AP Chem- we discussed thermochemical equations and did stoichiometric examples involving the heat/energy absorbed or released from various quantities of reactants or products.
DO NOT FORGET that the delta H value given for a reaction is PER MOLE of "reaction"; that is, for the reaction 2A + B --> 3C + D ; delta H = -255 kJ , one MOLE of reaction means that TWO moles of "A" reacted, ONE mole of "B" reacted, THREE moles of "C" formed, and ONE mole of "D" formed AND that 255 kJ of energy were released to the surroundings.
We discussed certain calorimetry terms "heat capacity", "specific heat (capacity), and "molar heat capacity"; these DEFINED measurements enable us to QUANTITATIVELY determine the energy gained or lost in a process or reaction. We also learned the qualitative meaning of each of these terms.
We demonstrated the very endothermic gas forming reaction of barium hydroxide and ammonium chloride, which forms water, ammonia gas, and aqueous barium chloride. We then started a descriptive chem set similar to what you will see on question 4 in part II of the AP exam.

Bio 6/7- we finished our Protein Synthesis Lab discussion and then launched our new unit on Photosynthesis and (Cellular) Respiration.
We discussed the big picture relationship between the two processes and where these processes occur. We then revisited the two types of nutrition to see that only AUTOtrophs can make glucose from inorganic CO2 and H2O via photosynthesis. Heterotrophs must eat/consume other organisms to get glucose and other nutrients.
We then defined photosynthesis and wrote out the NET word and the NET chemical equation for that process. There are actually many, many reactions involved in converting CO2 and H2O into glucose and oxygen but we will mainly focus on the starting reactants and theend products.

Bio 8- We discussed the big picture relationship between the two processes and where these processes occur. We then revisited the two types of nutrition to see that only AUTOtrophs can make glucose from inorganic CO2 and H2O via photosynthesis. Heterotrophs must eat/consume other organisms to get glucose and other nutrients.
We then defined photosynthesis and wrote out the NET word and the NET chemical equation for that process. There are actually many, many reactions involved in converting CO2 and H2O into glucose and oxygen but we will mainly focus on the starting reactants and the end products.

AP Chem- we reviewed the 0-th and 1st Laws of Thermodynamics, emphasizing the importance of understanding the SIGNS of heat and work with respect to the system. Once those signs are understood/felt, the math version of the 1st Law dE = q + w has to work and make sense. For example, if a system ABSORBS heat ( q is positive ), then the change in internal energy of the system MUST be positive due to the energy absorbed. If a system DOES WORK i.e. pushes a piston (w is negative), then that system LOSES energy (in order to do the work, it uses up some of its energy!) so the change in internal energy is negative. If both work and heat are involved, there may be a NET gain or loss of internal system energy depending on which value is greater and the sign of those values.
We then discussed ENTHALPY, which is a measure of the potential energy of the system's particles. The more stable the particles, due to MORE and STRONGER bonds, the LOWER the ENTHALPY of the system's particles. We can't measure absolute enthalpies (though we do DEFINE certain values, as you will see), we CAN via calorimetry, measure CHANGES in enthalpy, delta H, which we sometimes call the "heat of reaction" or "heat of some process".
We noted that change in enthalpy MUST BE measured ONLY under CONSTANT PRESSURE conditions and the ONLY type of work that can occur is gaseous pressure-volume work.
Try that descriptive chem set tonight; you can "grade" yourself on that tomorrow.

Bio 6- took our transcription and translation exam today. As you saw, you had already answered all of the test question types in the objectives hw. Further proof that putting in the time and effort on that homework makes the tests much more familiar and easier to handle.

Bio 7/8- took our transcription and translation exam today. As you saw, you had already answered all of the test question types in the objectives hw. Further proof that putting in the time and effort on that homework makes the tests much more familiar and easier to handle.
We then finished our Protein Synthesis lab.

AP Chem- looked over our generally well-written and calculated Gas unit exam. Please heed the advice to avoid careless errors on future tests. You are putting a lot of time and effort into your tests so you might as well go full throttle and check that you are doing things in detail with special attention to test-taking skills. Avoiding test skills costs you not only points, but also TIME because you spend time on questions that do not even exist.

We started thermo today by going over some basic definitions and formulas. It is very important that these concepts MAKE SENSE to you from the beginning because you won't know what SIGNS to use or how to relate the various state functions as we get more practically into the unit. Study and review the notes each day; you can also check out the many tutorials that I am posting for this dry, direct, INSIDE-the-box unit.

Bio (all) - we discussed translation, transcription, mutations and the various test skills for tomorrow. I just posted another practice quiz and unit summary as well as the solutions to today's worksheets. The hw's looked pretty solidly aligned with the state objectives for the Regents and for your similar test tomorrow so good luck, follow the test skills advice, and I look forward to seeing you show off your knowledge.

AP Chem- we went through our REDOX (not acid-base!) titration lab, drawing out the equipment used, reactions involved, and proper techniques performed.
This lab is due Thursday the latest but you should finish it this weekend because we will be deep into the next unit by Wednesday and you will have to focus on that hw then.
Continued success in the second quarter! So far, the gas unit exam is looking quite good; the few exceptions involve NOT identifying and using keywords in the question, in which case you cannot possibly answer the question that was asked, and also, not labeling the substances involved, which resulted in calculation of the quantity of the wrong substance. Please heed the written helpful rules that appear at the end of every test (but that won't be there for you on the AP exam, by which time you'll do them automatically, of course).

Bio 6- Friday's notes and worksheet answers are posted.
We discussed the various mutation types and the effects that they ultimately have on the proteins formed and the altered traits or lack of a given trait that can be caused by these mutant shaped proteins.
We will finish our protein synthesis lab discussion and do unit test review on Monday.

Bio 7/8- Friday's notes and worksheet answers are posted.
We discussed the various mutation types and the effects that they ultimately have on the proteins formed and the altered traits or lack of a given trait that can be caused by these mutant shaped proteins.
We drew out and saw that "silent" mutations, though they involved a substituted nucleotide/slightly changed base sequence in the DNA, do not cause a different protein to be produced or coded for. This is because, in a silent mutation, the mutated codon codes for the SAME amino acid in the protein/polypeptide chain. There are only 20 different amino acids BUT there are 64 different DNA codons (triplet combinations of A,T,G,and C) so some of the DNA codons code for the SAME amino acid.

AP Chem- took the Gas Unit exam today. Tomorrow, we will dedicate most of the period to discussing the lab and writeup of our solution stoichiometry titration of bleach/hypochlorite ion and possibly the Boyle lab. Our next unit is on Thermochemistry, which focuses on energy absorbed or released by a given physical or chemical process or processes. The rest of Thermodynamics, entropy and Gibbs Free Energy, are covered in April at the very end of our course .
Part I is graded...almost all got one or two multiple choice questions wrong...ONLY ONE of you got them all right (the one who knows Avogadro's Law...the most frequently tested law on the AP exam and on SAT II Chem...check that out). Starting to look at Part II's now...I hope that they are as good as my cursory impression of them!

Bio 6/7- the objectives HW is due Friday; you can skip objective # 9 or just copy this answer that you already know from our biochemistry unit: Five protein types that are possible to form via translation are (1.) enzymes, (2.) transport proteins, (3.) antibodies, (4.) receptor proteins, (5.) certain hormones (e.g. insulin) ( you can also put "recognition proteins", light-absorbing proteins such as chlorophyll, oxygen-transporting proteins such as hemoglobin).
We didn't finish our Protein Synthesis lab discussion but we will do so tomorrow.

We discussed substitution point mutations as well as "frameshift" addition/insertion and deletion mutations. We then looked at gross/large chromosomal mutations i.e. chromosomal deletions, chromosomal insertions, chromosomal inversions, and chromosomal translocations.
We will wrap up the unit tomorrow and complete our test review on Monday; we have more time to review so this test should be our best yet!

Bio 8- the objectives HW is due Friday; you can skip objective # 9 or just copy this answer that you already know from our biochemistry unit: Five protein types that are possible to form via translation are (1.) enzymes, (2.) transport proteins, (3.) antibodies, (4.) receptor proteins, (5.) certain hormones (e.g. insulin) ( you can also put "recognition proteins", light-absorbing proteins such as chlorophyll, oxygen-transporting proteins such as hemoglobin).

We discussed substitution point mutations as well as "frameshift" addition/insertion and deletion mutations. Tomorrow, we will discuss gross/large chromosomal mutations i.e. chromosomal deletions, chromosomal insertions, chromosomal inversions, and chromosomal translocations.
We will wrap up the unit tomorrow and complete our test review on Monday; we have more time to review so this test should be our best yet!

AP Chem: tomorrow is the Gas unit test day. Anticipate questions on each subtopic covered in the unit with ONE exception: writing the reactants and products of the FOUR specific types of "gas-forming" reactions will not be tested although, if these reactions are on the test, the equation will be given. (You will be tested on a myriad of reaction types on your Thermochemistry exam in a couple of weeks; we will have had more practice by then, though I know that you already know the gas-forming reaction types.)
So, make sure that you practice your
1. gas stoichiometry (we did at least three problems IN CLASS and there are dozens of problems on the practice tests/worksheets),
2. Dalton's Law (in all of its forms) problems,
3. Graham's Law (in its two forms, time OR rate given) problems,
4. the Ideal Gas Law in ALL of its permutations (Boyle, Charles, Gay-Lussac, Avogadro, and molar mass to density and vice-versa) numerically and graphically,
5. Kinetic-Molecular Theory explanations of each gas law (according to the TWO bullet points, in detail),
6. explaining how and why and under which conditions gases behave ideally or otherwise deviate from ideal gas behavior,
7. the Van der Waal's equation and the meaning of each correction factor and explaining the relative magnitude of the a or b factor for each gas in a set of gases.
As usual there will be NO surprises and, if you solve the problems as seen in class (re-do the notes posted online) and also do the problems supplemented in the hw and worksheets/practice tests, you will just be repeating what you already have done many times. That is how can excel or continue to do so in our new quarter. Never easy, always possible/likely for each of you.

Bio 6- HW Objectives have been posted on Blackboard since last week; the hw is due Friday and your unit test is next Tuesday.
Today, we REVIEWED transcription and translation via a worksheet; we then began to look at the last part of our unit: genetic mutations. We saw an overview of the two major types of mutations: point mutations and (much larger) chromosomal mutations.
We will do an example of each specific type, tomorrow.

Bio 7/8-HW Objectives have been posted on Blackboard since last week; the hw is due Friday and your unit test is next Tuesday.
Today, we REVIEWED transcription and translation via a worksheet; we then began to look at the last part of our unit: genetic mutations. We saw an overview of the two major types of mutations: point mutations and (much larger) chromosomal mutations.
We will do an example of each specific type, tomorrow.
We then did a lab simulation on DNA transcription and mRNA translation into a particular amino acid sequence that formed a protein/polypeptide that was involved in some nerve pathway to make you have a certain behavioral TRAIT.

UPDATE: the NOTES from Monday's class are now posted on Blackboard!

AP Chem- Chapter 5 Gas Unit HW is due on Wednesday. I will post a video if many of you are having trouble with a particular problem, though I do not expect that since we did each problem type in the notes. NOTE: for question 85, you must use Table 5.3 on page 224 of the text to get the Van der Waal's correction factors for Nitrogen gas.

We collected the data for our Boyle's Law lab. The purpose so far is just to familiarize each of you with the Pasco interfaces and software. I will give you the writeup instructions on that AFTER we finish the redox titration lab writeup (one lab at a time, overall).

We then finished our stoichiometry/Dalton's Law problem involving the collection of a gas over water. The BIG hint in these problems is that the VAPOR PRESSURE of water at the experiment's TEMPERATURE will be given in the data! You MUST subtract that water vapor pressure from the TOTAL gas pressure to get the partial pressure of the "other" gas that is in the collection tube.
The point of most of these problems is to get the PARTIAL pressure of a given gas, convert it to moles of THAT PARTICULAR substance, use that number of moles in the BALANCED chemical equation in order to get the moles/grams/liters/particles of some other reactant or product in the reaction.
We then discussed the 4 postulates/assumptions required to derive (on paper, even!) the ideal gas law.
Any gas that eschews/deviates from those four postulates due to, say, low temperature and/or high pressure, will no longer obey the ideal gas equation.
Van der Waal's, in order to make the ideal gas equation "work" for real gases, developed EMPIRICALLY/VIA EXPERIMENT some "correction factors", "a" and "b", to account for the actual intermolecular attractions ("a") that exist between all gas molecules and to account for the actual particle volumes ("b") that each gas molecule has.

Bio 6/7- we reviewed transcription and translation, looking at several more detailed diagrams of the processes.
We finished our plant and animal cell mitosis lab discussion and then we began a lab simulation in which you "became"/acted out the mRNA and tRNA molecules involved in transcription and translation. You transcribed the DNA code in the nucleus/"front of the room" into an mRNA molecule which then via facilitative diffusion/"went to the ribosomes at the back of the room" where particular tRNA anticodons were attracted to the mRNA codons of your mRNA molecule. You wrote down the sequence of amino acids that were brought along by the tRNA molecules. For fun, to see what "behavior" the protein caused, we associated the amino acid sequence with a particular sequence of words/ a sentence that caused a particular behavior.

Bio 8- we reviewed transcription and translation, looking at several more detailed diagrams of the processes. We also finished our plant and animal cell mitosis lab discussion.

AP Chem- The ONLY (there CANNOT be any more quarterly bonus tests for the rest of this course) quarterly bonus test for the year will be given on Monday after school (starting some time between 3:45 PM and 4:00 PM) in Room 308. The objectives covered on this MULTIPLE CHOICE TEST will be posted on Blackboard this weekend. You should RETAKE ALL of your previous tests and quizzes from the first quarter to START your review. Let the ease or difficulty of these past tests guide the rest of your study. ALL previous unit files and practice tests are STILL on Blackboard. This 100 point test cannot hurt your quarterly average; it can only help further prepare you for the AP exam and possibly help your first quarter average.

We applied Graham's Law of Effusion to two problems in which we compared the relative RATES of effusion of two different gases and then used the relative times of effusion in order to determine the molar mass of an unknown gas.
The ideal gas law can be used to derive (we didn't go through that; unnecessary) the average (root mean squared) speed of a molecule because T is a measure of average kinetic energy and average kinetic energy is proportional to the mass of the molecule times its velocity squared.
We saw that the official AP CHEMISTRY REFERENCE TABLE foolishly gives a "wrong" version of the rms (average) speed of a gas molecule at a given Kelvin temperature. To correct the formula so that we can use the common molar mass measurement of grams per mole, you must change the "3" to a "3000" and use the units of grams per kg. Then, the Joule unit (from "R") will cancel and you will be left with the speed in meters per second.
We then revisited Dalton's Law of Partial Pressure, which is frequently used in gas stoichiometry problems in which the lab procedure dictates that the gaseous product be collected over WATER. This ALWAYS (at ANY temperature) causes the collected gas to be mixed with water vapor (a gas!). Therefore, Dalton's formula must be used.

Bio 6- we reviewed TRANSCRIPTION and then focused on the subsequent process of TRANSLATING the mRNA code/sequence of RNA bases to a sequence of amino acids that form the "trait-causing" protein. We saw the tRNA is required to complement/pair with mRNA triplets/codons. Each particular tRNA anti-codon will cause a particular amino acid to be attached/bonded to the tRNA molecule. We saw the mRNA codon chart that shows the particular amino acid that will be transferred by the tRNA at the ribosome to make the amino acid chain/protein.
I will post a translation video on Blackboard this weekend. I will also put your lab grades up this weekend (except for the whitefish blastula/onion root tip mitosis lab IF you didn't finish that yet).

Bio 7/8- we reviewed TRANSCRIPTION and then focused on the subsequent process of TRANSLATING the mRNA code/sequence of RNA bases to a sequence of amino acids that form the "trait-causing" protein. We saw the tRNA is required to complement/pair with mRNA triplets/codons. Each particular tRNA anti-codon will cause a particular amino acid to be attached/bonded to the tRNA molecule. We saw the mRNA codon chart that shows the particular amino acid that will be transferred by the tRNA at the ribosome to make the amino acid chain/protein.
We then finished our plant and animal cell mitosis lab; we will quickly discuss the questions on Monday so that the lab can be entered last minute for the first quarter.

AP Chem- we saw the various gas laws graphically as we sketched the data from the tables we had developed from the ideal gas equation. Each law is really just the ideal gas law with certain variables held constant.
We then EXPLAINED in terms of "kinetic-molecular theory", which is just a fancy term for molecular collision frequency and kinetic energy of the collisions, Boyle's Law.
I posted the full explanation of each of the other gas laws. Peruse them and let me know if there is any process that does not make sense to you.
We also discussed the natural "Bolzmann distribution" of molecular speeds at a given temperature and saw how different gases are traveling at different speeds at a given temperature. That is because (Kelvin) temperature is directly proportional to the average kinetic energy of the molecules/particles of a substance and not just the speed of the molecules/particles. So, the mass of the molecules accounts for the different average speeds of different molecules even when they are at the same temperature.
We used this information to derive Graham's Law of Effusion (diffusion through a pinhole).

Bio 6/7- we reviewed our last exam and went over some important test-taking skills (pre-phrasing answers, writing/drawing out predicted answers, legal cheatsheets, etc.).
We then continued our discussion of transcription of DNA to mRNA and then translation of the mRNA code/pattern into a protein (specific number and sequence of amino acids).
I posted the video that we saw today on Blackboard.
We finished up our plant and animal mitosis lab, which you will hand in tomorrow after we discuss some of the questions.

Bio 8 -we reviewed our last exam and went over some important test-taking skills (pre-phrasing answers, writing/drawing out predicted answers, legal cheatsheets, etc.).
We then continued our discussion of transcription of DNA to mRNA and then translation of the mRNA code/pattern into a protein (specific number and sequence of amino acids).
I posted the video that we saw today on Blackboard.

AP Chem- GREAT NEWS so far... I just graded six Stoichiometry exams in a row and ALL of them were A's or better! Hoping that the streak continues...right now, I'll just bask in your excellent achievement on this difficult exam.
we did some descriptive chemistry, writing and balancing the formula and net ionic equations for each of the four common "gas forming" reactions. We noted that ALL molecules are always written with their complete formula with ONE exception: STRONG acid molecules (there are ONLY SIX of them) are written with the FIRST H+ ionized along with the resulting anion X-.
Soluble salts are written as SEPARATE/dissociated AQUEOUS ions (if in aq. solution), insoluble salts are with their complete formula and kept in the solid (insoluble) phase. Strong bases are written as separate dissociated hydroxide ions (and the cation, M+) whereas weak bases are written with their complete undissociated formulas.
We then looked at the various "versions" of the ideal gas law: Boyles's, Charles's, Gay-Lussac's, and Avogadro's Laws are really the ideal gas law with certain variables held constant.
Tomorrow, we will explain the CAUSES of each gas law in terms of "kinetic-molecular" theory, which is just a fancy way of saying (1) molecular collision frequency and (2) force of molecular collisions.

Bio 6- we began our new unit on Transcription and Translation, which makes up the central DOGMA of molecular biology. These two processes account for/cause ALL of your traits/potentials!
We saw the OTHER major purpose of DNA: to act as a template/pattern for mRNA, which takes the DNA code to the ribosomes where that coded information is "translated" into the particular sequence and number of amino acids that make up the proteins that CAUSE your traits.

Bio 7/8 - we began our new unit on Transcription and Translation, which makes up the central DOGMA of molecular biology. These two processes account for/cause ALL of your traits/potentials!
We saw the OTHER major purpose of DNA: to act as a template/pattern for mRNA, which takes the DNA code to the ribosomes where that coded information is "translated" into the particular sequence and number of amino acids that make up the proteins that CAUSE your traits.

AP Chem- Here is the Unit 5 Gases HW: text pages 187-230, do the following problems to be handed in next week (will post the exact date later):
32, 46, 52, 68, 74, 80, 82, 85, 108, 112
We applied the "density to molar mass" version of the ideal gas law in which we are given either grams of gas, volume, temperature, and pressure to determine the gas's molar mass or we are given a known gas (or its molecular formula), its mass, temperature, and pressure to determine its density under those SPECIFIC conditions (remember that the density of a gas varies with temperature and pressure).
We then derived Dalton's Laws of Partial Pressure, which are fairly obvious, if you draw a picture of gas molecules in a container and understand that the molecular collisions with the container and each other cause the pressure. We saw that the NUMBER of molecules (or MOLES of molecules) of a given gas determines that gas's contribution to the total pressure; we also noted that the sum of all of the gases' partial pressures must equal the total pressure due to the gases in the container (which sounds quite circular in reasoning!).
The partial pressure of a given gas equals its MOLE FRACTION times the total gas pressure in the container.
We then did a gas stoichiometry problem (just like any other stoichiometry problem, really) that looked a bit different due to the bulb apparatus that keeps the gaseous reactants initially separate. In these problems, you do have to take into account that the entire container volume is used once the valve is opened to let the gases mix and/or react!
We saw that this was a typical limiting reactant problem in which we determined all mole quantities by using the ideal gas law. We then used Dalton's Laws to get the partial pressure of each remaining gas.
Finally, we started/continued our ultimately long practice with descriptive chemistry by discussing the four KEY gas-forming reactions.

Bio 6/7- took the Mitosis, DNA, Asexual Reproduction exam. Then we finished the data collection on the Mitosis Lab and the Osmosis in the Onion Cell Lab.

Grading the test, I noticed that many of you made careless errors by NOT identifying/underlining/circling key terms in the question and using those terms in your answer; to avoid losing points needlessly in the future, do not forget this when you see your easily avoidable errors on your test papers.
Overall, the class average was high though (but it could have been even higher).

Bio 8- took the Mitosis, DNA, Asexual Reproduction exam. Grading the test, I noticed that many of you made careless errors by NOT identifying/underlining/circling key terms in the question and using those terms in your answer; to avoid losing points needlessly in the future, do not forget this when you see your easily avoidable errors on your test papers.
Overall, the class average was high though (but it could have been even higher).