SciHawks

Just finishing playing (and missing every shot) at the charity basketball game in the gym tonight. Will update the blog and post all files by Saturday afternoon.
Have a good weekend (and study too!).


AP Chem- we reviewed kinetic mechanisms in which the rate law predicted from each elementary step does not match the experimental rate law, per se. However, in a case in which an EARLIER (almost always the FIRST step) is FAST and reaches EQUILIBRIUM before the rate determining SLOW step is significantly underway, a SUBSTITUTION can be made into the slow step's rate law after which the rate law predicted MAY agree with the experimental rate law. The first thing that you should check, though, in a mechanism is whether the SUM of the elementary steps adds up to the BALANCED equation.
We then discussed and derived the equations and sketched the various graphs of data for a
ZEROTH order rate law (usually photon-catalyzed decompositions!) and 1ST order rate laws (in which ONE molecule/atom/ion of a given substance is involved in the rate determining step.
We also made a KEY table showing the units of a rate constant, "k", for each of the zeroth, first, second, etc. overall rate law types.

I will post practice problems on Blackboard. Check out the tutorials also.

Bio 6/7- we discussed the structure and function of each part of the excretory system (and diseases thereof) and then we showed any given two systems in your body are working together to overall maintain homeostasis.
Check the review worksheets, quizzes, and objectives answers as part of your study for MONDAY's exam.

Bio 8- we looked at four major respiratory system diseases and then we discussed the structure and function of each part of the excretory system and then we showed any given two systems in your body are working together to overall maintain homeostasis.
Be sure to read in your notes about gout and kidney stones as excretory system diseases.
Check the review worksheets, quizzes, and objectives answers as part of your study for MONDAY's exam.

AP Chem- be sure to keep apace of the descriptive chemistry practice problem sets; we were going to have a descriptive chem quiz tomorrow but I will give that on Monday.
We reviewed how to write a rate law for an elementary step of a proposed mechanism; we then saw how to relate the EXPERIMENTALLY DETERMINED rate law to the expected rate law from the SLOW STEP of a proposed mechanism. However, when there is not a direct match between the proposed and expected rate laws, one must SUBSTITUTE for one of the reactants (the one that is NOT in the experimentally determined rate law) by solving for that reactant in a prior FAST elementary step that has reached EQUILIBRIUM i.e. the forward and reverse rates are equal in that step. We applied this method to two problems to see that the proposed mechanism rate law actually does agree with the experimentally determined rate law.

We then informally saw how rate laws are actually determined/inferred from the experimental data. Skill with exponents and multiplication is the main requirement!

Bio: PLEASE NOTE! Though we had no school yesterday AND even though there was a Math A Regents exam for most of the class, our UNIT EXAM on the circulatory, respiratory, and excretory systems is STILL ON MONDAY as decreed by the Biology Department.

We will cover the excretory system in its entirety on Friday. I will post the notes AND videos on Blackboard so that you can preview tomorrow's lesson and worksheets (especially if you are in Period 8 because we only have 40 minutes!).
The hw objectives are due tomorrow EXCEPT for the excretory system and the combined systems objectives, specifically objectives 9 through 13 will NOT be graded, though you should look at them before tomorrow.

I will post my complete answers to all objectives tomorrow afternoon so make sure that you study those answers as part of your preparation for Monday's exam.

The dangerous chemical, "dihydrogen monoxide", in its perilous, solid form, has been found on most Long Island roads. Though most of this odious compound has been plowed away and "cured" with sodium chloride, authorities consider it imprudent to venture outside with the remnants of this noxious chemical still present on our roads.

AP Chem- Kinetics waits for no person! This is a good day to begin the unit hw, now that we have covered some ground.
I'll give you the complete hw problem set on Thursday, but for now do the following problems at the end of Chapter 12: (show all work) 18, 19, 20, 46, 48 59a, 59b, 60, 68

Bio Classes: Review the Respiratory System and Circulatory System videos on Blackboard and continue to work on your HW objectives. I will collect the objectives on either Friday or Monday, depending on the date of our unit exam.

AP Chem- we finished our transition metal-ligand complex lab by discussing the bonding within :coordinate covalent bonds between the ligand with the available lone pair and the metal cation with the empty hybridized orbitals. We also accounted for the solubility of these transition metal ion complexes due to their overall low charge density allowing for multiple ion-dipole attractions to overcome the ionic bonding of the lattice.

We returned to Kinetics by showing how to write an EXPECTED rate law from a PROPOSED elementary step of a mechanism; you simply write "rate" = k times the concentration of each REACTANT (not product) to an EXPONENT (equal to the NUMBER of atoms/molecules/ions of that substance in your elementary step).
The rate law for the SLOW step of your mechanism, the step with the HIGHEST activation energy, the step that DETERMINES the overall rate of the reaction (as we showed by analogy in class) should agree with/equal/match the EXPERIMENTALLY DETERMINED rate law. If your slow step rate law does not match the experimental rate law, the mechanism is wrong with ONE EXCEPTION that we will discuss tomorrow. We will also discuss HOW to mathematically obtain a rate law from EXPERIMENTAL DATA (fun with exponents).

Bio 6/7- we reviewed the parts of the blood and then we saw videos (available on Blackboard!) on the respiratory system and on the mechanics of breathing; we then discussed the mechanism by which the medulla oblongata detects the elevated carbon dioxide level in the blood and sends a neurochemical signal to the diaphragm, causing the diaphragm to contract, which expands the chest cavity, which lowers the air pressure in the lungs, causing the higher pressure air outside of the body to rush into the lungs i.e. inspiration. The diaphragm then relaxes/pushes up on the lungs, increasing the air pressure in the lungs, which forces the air out of the lungs causing exhalation, which rids the blood of excess carbon dioxide. The cycle then begins again as body cells, which are constantly producing carbon dioxide via aerobic respiration, have their carbon dioxide diffuse into the blood.
We then started to compile the resting and post-exercise pulse rate data from our last lab.

Bio 8- we reviewed the parts of the blood and then we saw videos (available on Blackboard!) on the respiratory system and on the mechanics of breathing; we then discussed the mechanism by which the medulla oblongata detects the elevated carbon dioxide level in the blood and sends a neurochemical signal to the diaphragm, causing the diaphragm to contract, which expands the chest cavity, which lowers the air pressure in the lungs, causing the higher pressure air outside of the body to rush into the lungs i.e. inspiration. The diaphragm then relaxes/pushes up on the lungs, increasing the air pressure in the lungs, which forces the air out of the lungs causing exhalation, which rids the blood of excess carbon dioxide. The cycle then begins again as body cells, which are constantly producing carbon dioxide via aerobic respiration, have their carbon dioxide diffuse into the blood.

AP Chem- we showed how to graphically determine the rate constant for a given reaction given the changing rate of reaction vs. the concentration of a given reactant or product to a particular POWER/EXPONENT. The slope of the line from this plot is the value of the rate constant and the ONLY factor that can CHANGE the rate constant for a given reaction is the TEMPERATURE.

The exponent used in order to yield a straight line for the plot tells the ORDER or MOLECULARITY of that PARTICULAR reactant in the "rate-determining" step of the reaction mechanism. That means that if rate = k [A]^2, there must be TWO "A" molecules involved in the collision in the particular step of the reaction mechanism that essentially determines the RATE of the whole reaction (some steps occur extremely quickly, others slowly; it's the slow steps that determine the rate of the overall reaction, as we will discuss tomorrow).

Related to the above, we discussed how to write a rate law from PROPOSED elementary steps of a reaction mechanism.
For example, the elementary step A + C --> Q would have a rate law of : rate = k [A] [C]
showing an overall ORDER or MOLECULARITY of 2 but an order/molecularity of 1 for EACH of A and C (they are both to the 1st power).

Basically, we are in the midst of relating a proposed mechanism for a given reaction to its EXPECTED mathematical rate law; we then COMPARE the expected mathematical rate law to the ACTUAL experimental data. I will show you how to write a rate law from actual experimental data (always 3 or more experimental trials); if you have facility with exponents, then you might actually enjoy the slight deciphering of the experimental data required.

Bio 6- we began the respiratory system part of our unit by discussing the structure and function of each component. We saw how each part of the respiratory system aids in increasing the diffusion of oxygen into the blood: the nasal passages help to filter, warm, and moisten the oxygen/air, the epiglottis prevents the clogging of the lungs with food or drink, the trachea remains sturdy due to its rings of cartilage (it also has additional cilia for more filtration especially of the air that enters through the mouth), the alveoli are rounded and are in bunches surrounded by beds/webs of capillaries to maximize surface area for oxygen and carbon dioxide exchange.
We briefly discussed the breathing mechanism, which we will elaborate on tomorrow.

Bio 7/8- we finished the circulatory system by discussing the "fluid" that is pumped through the vessels by the heart; that fluid is the blood, which is composed of red blood cells (erythrocytes), white blood cells, platelets, and plasma. Blood is the connective tissue that links all parts of the body.
The red blood cells, which contain no nucleus, transport oxygen to body cells from the lungs and transport carbon dioxide from body cells to be excreted by the lungs.
There are several different specific white blood cells, but they all are involved in your immune system, helping your body to maintain homeostasis by preventing harmful substances, cells, or organisms from entering or affecting your body.
The platelets help to form blood clots to prevent bleeding from broken blood vessels; you have a CLOSED circulatory system so all of the blood is ENCLOSED within vessels that must remain free from holes or punctures to contain the blood; platelets aid in plugging up any breaches in these vessels.
The plasma contains dissolved and undissolved (mixed) enzymes, vitamins, minerals, sugars, fatty acids, amino acids, hormones, nucleotides that are transported to the various cells of the body.

We then began our focus on the system that works in cooperation with the circulatory system:
the RESPIRATORY system.
We recalled the two types of CELLULAR respiration: aerobic and anaerobic.
The oxygen needed by cells (mitochondria) for aerobic respiration is obtained by the functioning of the respiratory system and transported to the cells via the circulatory system.
We discussed the structure and function of each component of the respiratory system. We saw how each part of the respiratory system aids in increasing the diffusion of oxygen into the blood: the nasal passages help to filter, warm, and moisten the oxygen/air, the epiglottis prevents the clogging of the lungs with food or drink, the trachea remains sturdy due to its rings of cartilage (it also has additional cilia for more filtration especially of the air that enters through the mouth), the alveoli are rounded and are in bunches surrounded by beds/webs of capillaries to maximize surface area for oxygen and carbon dioxide exchange.

AP Chem- the IMFA/Raoult test scores are now posted! Good job (but some molecular/electronic geometry errors after you all got those right last time...how??? review that please). Class average was 136 out of 150 or 91%...three-peat!
We discussed the remaining factors that can influence:
1. collision frequency
2. orientation of collisions (not all bond breakage will result in the formation of the specific STABLE main product of the given reaction)
3. force/KE of the collision

These factors are: temperature (which is the ONLY factor that simultaneously affects factors 1 AND 3!), surface area of a LIQUID or SOLID (you cannot increase the surface area of a gas- there is NO surface!), and the addition (or removal) of a catalyst (which is the ONLY factor that can affect the PERCENTAGE of collisions that have proper bond-breaking ORIENTATION).

We then discussed HOW rates of chemical reactions are measured and WHY the preferred measurement is in units of change in MOLARITY (rather than just moles) per second- this way the scientist can "sample" the reaction mixture without affecting the concentration even though s/he is affecting the remaining number of moles in the mixture.
We then saw how to write the RATE EXPRESSION for a given reaction based on the COEFFICIENTS of the reactants and products in a BALANCED equation. This way, when you measure the rate of DISAPPEARANCE of a given reactant, you automatically can calculate the rate of APPEARANCE of a given product based on the STOICHIOMETRY of the reaction. Also, you can determine the rate of reaction (PER MOLE OF REACTION!) given the rate of disappearance of any reactant OR the rate of appearance of any product.
I will post some practice problems on Blackboard for this weekend. DO THESE before Monday because we have a lot more and different material to cover in this unit.

Bio 6/7- We went through a complete example showing the key areas of carbon dioxide and oxygen diffusion/exchange between the blood and body tissue (alveolar/systemic/or coronary) cells.
we finished the circulatory system by discussing the "fluid" that is pumped through the vessels by the heart; that fluid is the blood, which is composed of red blood cells (erythrocytes), white blood cells, platelets, and plasma. Blood is the connective tissue that links all parts of the body.
The red blood cells, which contain no nucleus, transport oxygen to body cells from the lungs and transport carbon dioxide from body cells to be excreted by the lungs.
There are several different specific white blood cells, but they all are involved in your immune system, helping your body to maintain homeostasis by preventing harmful substances, cells, or organisms from entering or affecting your body.
The platelets help to form blood clots to prevent bleeding from broken blood vessels; you have a CLOSED circulatory system so all of the blood is ENCLOSED within vessels that must remain free from holes or punctures to contain the blood; platelets aid in plugging up any breaches in these vessels.
The plasma contains dissolved and undissolved (mixed) enzymes, vitamins, minerals, sugars, fatty acids, amino acids, hormones, nucleotides that are transported to the various cells of the body.

We discussed some of the common diseases of the cardiovascular system.
Hypertension, which is high blood pressure, can have many independent and cumulative causes such as stress, genetics/heredity, diet, and substance abuse.
Recall the first measurement of a blood pressure reading is the systolic (SQUEEZE) pressure (typically 100 to 150 mmHg) and the second measurement is the diastolic pressure (when the heart is "relaxed" as blood goes from the atria to the ventricles (not a high-force contraction).

We discussed two similar heart attack- causing conditions:
1. coronary thrombosis, in which a thrombus- a mass of cholesterol or a blood clot particle- attaches to some plaque on the inside of a coronary artery causing a blockage of the artery.
The red blood cells are then blocked from delivering oxygen to certain heart cells and a heart attack may ensue.

2. angina pectoris is the NARROWING of coronary arteries due to deposits of cholesterol or some other plaques on the inner walls of the arteries. This causes an insufficient number of red blood cells to deliver oxygen to certain heart muscle cells.

Other circulatory system disorders are HYPERTENSION (high blood pressure, which can be influenced by diet, genetics, and exercise) and hemophilia, the lack of a certain blood clotting factor (due to a mutant clotting factor allele in a person's chromosomes) can cause a person to internally bleed to death if blood vessels are cut or ruptured.
We finished our intracellular digestion lab writeup.

Bio 8- We went through a complete example showing the key areas of carbon dioxide and oxygen diffusion/exchange between the blood and body tissue (alveolar/systemic/or coronary) cells.
we finished the circulatory system by discussing the "fluid" that is pumped through the vessels by the heart; that fluid is the blood, which is composed of red blood cells (erythrocytes), white blood cells, platelets, and plasma. Blood is the connective tissue that links all parts of the body.
The red blood cells, which contain no nucleus, transport oxygen to body cells from the lungs and transport carbon dioxide from body cells to be excreted by the lungs.
There are several different specific white blood cells, but they all are involved in your immune system, helping your body to maintain homeostasis by preventing harmful substances, cells, or organisms from entering or affecting your body.
The platelets help to form blood clots to prevent bleeding from broken blood vessels; you have a CLOSED circulatory system so all of the blood is ENCLOSED within vessels that must remain free from holes or punctures to contain the blood; platelets aid in plugging up any breaches in these vessels.
The plasma contains dissolved and undissolved (mixed) enzymes, vitamins, minerals, sugars, fatty acids, amino acids, hormones, nucleotides that are transported to the various cells of the body.

We discussed some of the common diseases of the cardiovascular system.
Hypertension, which is high blood pressure, can have many independent and cumulative causes such as stress, genetics/heredity, diet, and substance abuse.
Recall the first measurement of a blood pressure reading is the systolic (SQUEEZE) pressure (typically 100 to 150 mmHg) and the second measurement is the diastolic pressure (when the heart is "relaxed" as blood goes from the atria to the ventricles (not a high-force contraction).

We discussed two similar heart attack- causing conditions:
1. coronary thrombosis, in which a thrombus- a mass of cholesterol or a blood clot particle- attaches to some plaque on the inside of a coronary artery causing a blockage of the artery.
The red blood cells are then blocked from delivering oxygen to certain heart cells and a heart attack may ensue.

2. angina pectoris is the NARROWING of coronary arteries due to deposits of cholesterol or some other plaques on the inner walls of the arteries. This causes an insufficient number of red blood cells to deliver oxygen to certain heart muscle cells.

AP Chem- we began the Kinetics unit, which involves the rates of chemical reactions and the mechanisms by which they occur.
We discussed two of the factors that will affect the EFFECTIVE collision rate/frequency; the effective collision rate is possibly affected by THREE factors:
1. collision frequency
2. orientation of collisions (not all bond breakage will result in the formation of the specific STABLE main product of the given reaction)
3. force/KE of the collision
NOTHING else need be considered so ALL explanations of kinetics should address EACH of the above three factors.


The NATURE (covalently bonded molecules or solvated ions, for example) of the reactants CANNOT be altered for a given reaction but the strength of either the covalent or ionic bonds OR the strength of the intermolecular attractions or ion-dipole attractions will determine the fraction of molecules that have sufficient KE to overcome the activation energy at a given temperature. Naturally, the stronger the bonds or attractions within or between the reactant particles, the greater the activation energy that must be overcome to achieve an EFFECTIVE (bond or attraction- breaking) collision.
The CONCENTRATION of the reactants is important because an increase in reactant particle concentration will increase the collision frequency among the reactant particles though this factor will not change the PERCENTAGE of effective collisions (due to proper orientation or sufficient KE of collision), the overall NUMBER of effective collisions per second will increase.

Bio 6- We reviewed the structure and function of the heart. We noted that the heart has four chambers: two atria and two ventricles. We described the heart's pumping action: the two atria simultaneously beat, sending deoxygenated blood from the right atrium through the open right A-V valve to the right ventricle just below it while sending freshly oxygenated blood from the left atrium to the left ventricle. Then, in about one second, the two ventricles simultaneously contract, sending deoxygenated blood from the right ventricle to the lungs via the pulmonary arteries while oxygenated blood gets pumped from the left ventricle to the aorta.

The heartbeat that is heard ("lub-dub" sound) is the result of the A-V valves slamming shut to avoid backflow of blood from ventricles to atria after the atria have contracted ("lub") and then the "semilunar"/mitral valves strongly slamming shut ("dub") to avoid backflow of blood from aorta to left ventricle or from pulmonary arteries to right ventricle after the ventricles have contracted.

We discussed the three types/regions of blood circulation, each with a particular purpose:

systemic circulation: the most far-reaching circulation of blood throughout the body from the heart to aorta to arteries, arterioles, capillaries, venules, veins and back to the heart.

coronary circulation: the sending of blood FROM the heart TO the heart via coronary arteries; blockage of these arteries causes a heart attack.

pulmonary (lung) circulation: the transport of blood from heart to lungs and back to the heart so that oxygen can diffuse from the lungs to the red blood cells and that carbon dioxide can be released from the blood cells and diffuse into the lungs.

Bio 7/8- We reviewed the structure and function of the heart. We noted that the heart has four chambers: two atria and two ventricles. We described the heart's pumping action: the two atria simultaneously beat, sending deoxygenated blood from the right atrium through the open right A-V valve to the right ventricle just below it while sending freshly oxygenated blood from the left atrium to the left ventricle. Then, in about one second, the two ventricles simultaneously contract, sending deoxygenated blood from the right ventricle to the lungs via the pulmonary arteries while oxygenated blood gets pumped from the left ventricle to the aorta.

The heartbeat that is heard ("lub-dub" sound) is the result of the A-V valves slamming shut to avoid backflow of blood from ventricles to atria after the atria have contracted ("lub") and then the "semilunar"/mitral valves strongly slamming shut ("dub") to avoid backflow of blood from aorta to left ventricle or from pulmonary arteries to right ventricle after the ventricles have contracted.

We discussed the three types/regions of blood circulation, each with a particular purpose:

systemic circulation: the most far-reaching circulation of blood throughout the body from the heart to aorta to arteries, arterioles, capillaries, venules, veins and back to the heart.

coronary circulation: the sending of blood FROM the heart TO the heart via coronary arteries; blockage of these arteries causes a heart attack.

pulmonary (lung) circulation: the transport of blood from heart to lungs and back to the heart so that oxygen can diffuse from the lungs to the red blood cells and that carbon dioxide can be released from the blood cells and diffuse into the lungs.

We then began a lab in which we measured the effect of increased exercise/activity on the pulse rate. We will develop the discussion of this lab as we discuss the interaction of the respiratory and circulatory systems.

AP Chem- we took our final unit test of what is the typical "first semester" of college chem.
From here in it's Kinetics, Equilibrium, Acids-Bases, More Equilibrium, Even More Equilibrium, Thermodynamics, and Electrochemistry all the while doing hundreds of descriptive chem problems; then, a mad dash involving two weeks of practice AP Chem exams and then THE AP Chem exam 2009!

Bio 6/7- we went through the complete heartbeat cycle noting the structure and function of the heart's parts. We covered pulmonary circulation, which is just the circulation of blood between the heart and the lungs, and noted the exchange of oxygen and carbon dioxide that occurs in the capillaries of the lungs.
We then started a lab on pulse rate, which we will continue next lab period.

Bio 8- we went through the (almost)complete heartbeat cycle noting the structure and function of the heart's parts. We covered pulmonary circulation, which is just the circulation of blood between the heart and the lungs, and noted the exchange of oxygen and carbon dioxide that occurs in the capillaries of the lungs.

AP Chem- we discussed the various types of solids: atomic or molecular, covalent-network, ionic, and metallic. We saw examples of each solid type and discussed the intermolecular forces of attraction or the bonds that hold the lattice particles in place.
We related the strength of the attractive forces to the physical properties i.e. typical melting point range of each type of solid; we discussed the simplified reason for electrical conductivity (NET movement of electrons through a lattice or ions in the liquid or aqueous phase) in metals as well as the non-conductivity of the other solid types.

Bio 6- we reviewed the digestion/endocrine system test, discussing graphing and test skills.

Bio 7/8- we watched the historic presidential inauguration; then, we reviewed the structure of veins and arteries. We then looked at the mechanics of the heartbeat: we saw a video showing the sequential contractions of the atria and the ventricles; we traced the flow of blood from each chamber of the heart and noted whether the blood was higher in oxygen/lower in carbon dioxide or vice versa.

AP Chem- we went through detailed explanations of the causes of molecular polarity in terms of bond polarity in combination with molecular geometry; we related the molecular polarity to the type of intermolecular forces of attraction, which is then used to account for physical properties such as melting and boiling points as well as miscibility in a given solvent (LIKE DISSOLVES LIKE).
I'll post more info about Wednesday's exam later; in the meantime, check out all of the tutorials and practice problems on Blackboard.

Bio 6/7- we began our new unit on the circulatory, respiratory, and excretory systems and then finished our discussion of the intracellular digestion lab.

Bio 8- we began our new unit on the circulatory, respiratory, and excretory systems

AP Chem- we looked at several examples of molecules, drawing the Lewis structure of each and determining the central atom hybridization, determining the electronic and molecular geometries, the bond dipoles, the overall symmetry or asymmetry of the charge distribution, the polarity of each; finally, from this information, we inferred the type of IMFA for each molecule from which we can make predictions or explain the physical properties of each substance.
We will do some more examples and then discuss the various types of bonding found in solids to finish our unit tomorrow.
Tuesday, we start the final half of the course with a primarily mathematical topic that will be mostly brand new to you:
KINETICS!
Our Raoult's Law, etc. and IMFA unit exam will be given next Wednesday; I'll stay after school tomorrow to give a proctored practice test. If you cannot stay for that, you are better off doing the practice files and worksheets that are on Blackboard (because they have an ANSWER key), though you can still have a copy of the practice test, which you should take strictly timed.

Bio 6- took the unit exam on the digestive and endocrine systems.

Bio 7/8 - took the unit exam on the digestive and endocrine systems and then discussed and handed in our latest lab on intracellular digestion in the Paramecium.

AP Chem- we did some problems involving the 3-phase pressure vs. temperature diagrams, answering questions about highest-density phase, normal boiling and freezing points, and phase changes under changing conditions.
We then began the finale of our unit on IMFA's by considering the dipoles that form in polar covalent bonds and how these dipoles are distributed depending on the electronic and molecular geometries. We use the molecular polarity to determine the primary (and possibly secondary) types of intermolecular forces between/among the molecules of a substance.

Bio 6/7- we reviewed for the digestive/endocrine system unit exam and then we discussed our intracellular digestion lab.

Bio 8- we reviewed for the digestive/endocrine system unit exam.

AP Chem- we discussed the measurement of vapor pressure and the relationship between the strength/type of IMFA's and vapor pressure. We saw how to read vapor pressure diagrams both horizontally and vertically in order to determine normal boiling point or vapor pressure at a particular temperature.
We then discussed the meaning and features of phase diagrams that show all three phases of a pure substance at various temperatures and pressures. We saw how to determine the phase of highest density (usually, but not always, the solid phase), the normal freezing and boiling points, the critical point, and the triple point.
We will finish our unit on bonding and intermolecular forces for the rest of the week.

Bio 6- we discussed diseases/disorders of the endocrine system and then started on an endocrine system/nutrition review worksheet. The answer key to that worksheet is posted on Blackboard; check that out as part of your review for Thursday's unit exam.

Bio 7/8- we discussed diseases/disorders of the endocrine system and then started on an endocrine system/nutrition review worksheet. The answer key to that worksheet is posted on Blackboard; check that out as part of your review for Thursday's unit exam.
Then we did a lab in which we tried to view intracellular digestion by a paramecium. Goodtimes.

AP Chem- note: there are additional practice Raoult's Law problems posted on Blackboard.
We did a couple more of the Raoult's Law molar mass problems, this time with a vastly simplified and easier to use formula. We can generalize about problems that ask for the molar mass of an unknown after they give you the grams of the unknown. The task then involves merely solving for the number of moles of the unknown.

We then discussed two types of Raoult's Law graphs: one plots vapor pressure vs. mole fraction of a two-component mixture and the other plots temperature/boiling points vs. mole fraction. The former graph shows the partial pressures of each component in the vapor phase given a particular mole fraction of each component in the liquid phase; the latter graphs shows the changing mole fractions as the vapor phase condenses and then is cooled to a new liquid mixture (as in a distillation column/apparatus) that has an increased mole fraction of the component that has weaker intermolecular forces. When this new mixture is vaporized and then condensed and cooled further, more separation of the two components of the mixture occurs.

We discussed metal-ligand complexes as forming from LEWIS acid-base reactions. The Lewis acid is the electron-pair ACCEPTOR i.e. the metal cation with the empty hybridized sp3d or sp3d2 orbitals ACCEPTS a lone pair of electrons from the ligand to form a coordinate covalent bond.
We will go over writing the descriptive chem answers and strategies for this type of reaction.
We will continue our transition metal lab writeup next double period.

Bio 6/7- Since we did not get to endocrine diseases/disorders, that objective will not be graded on tomorrow's hw.

We focused on a the adrenal glands and the pancreas, describing the endocrine/regulatory function of each. We then discussed THREE negative feedback loops that enable you to maintain homeostasis: the low blood glucose --> glucagon secretion via pancreatic cells --> increased blood glucose and glucagon --> negative feedback stopping of glucagon secretion

then, the high blood glucose --> insulin secretion via pancreatic cells --> decreased blood glucose and increased insulin --> negative feedback stopping of insulin secretion

finally, the low metabolic rate --> TRH secretion by the hypothalamus --> TSH secretion by the pituitary --> Thyroxin secretion by the thyroid --> increased metabolic rate and increased thyroxin level cause NEGATIVE feedback to pituitary AND hypothalamus, making them stop their secretion of TSH and TRH, respectively.

We attempted a paramecium intracellular digestion lab but there was a paucity of paramecia left in our supply jars. We will make up for that next time.

Bio 8- Since we did not get to endocrine diseases/disorders, that objective will not be graded on tomorrow's hw.

We focused on a the adrenal glands and the pancreas, describing the endocrine/regulatory function of each. We then discussed THREE negative feedback loops that enable you to maintain homeostasis: the low blood glucose --> glucagon secretion via pancreatic cells --> increased blood glucose and glucagon --> negative feedback stopping of glucagon secretion

then, the high blood glucose --> insulin secretion via pancreatic cells --> decreased blood glucose and increased insulin --> negative feedback stopping of insulin secretion

finally, the low metabolic rate --> TRH secretion by the hypothalamus --> TSH secretion by the pituitary --> Thyroxin secretion by the thyroid --> increased metabolic rate and increased thyroxin level cause NEGATIVE feedback to pituitary AND hypothalamus, making them stop their secretion of TSH and TRH, respectively.

AP Chem- we did two Raoult's Law problems: one in which the mole fractions and vapor pressures of two liquids are used to determine the vapor pressure of each component (from which you can calculate the total pressure simply by adding the partial pressures of each component) and then getting the mole fraction of each component in the vapor phase. These calculations are the quantitative basis of fractional distillation, a process by which the more volatile components of a mixture (WEAKER IMFA's) are separated from the less volatile components (STRONGER IMFA's) of the same mixture.
In the other problem, we used the vapor pressure lowering effect of adding a solute to a solvent to determine the molar mass of the solute.
One point of clarification that I will repeat on Monday and that you can read in the enhanced notes on Blackboard: we were GIVEN the grams of solute in the question and asked ONLY for the molar mass of the solute MEANING that we had to solve ONLY for the MOLES of solute (by using Raoult's Law) because if you find moles of solute and you already know the grams of solute, then you know the molar mass of the solute in grams per mole!
I used to detailed a formula in class by plugging in the known grams of solute; I should have (and DID do so in my own notes and thought process, which I ignored for whatever reason) just solved the simpler Raoult's Law formula for moles and then just used that value to divide into the given number of grams to get the molar mass in grams per mole. See the corrected solution in the notes on Blackboard.

Bio 6- We finished our lab discussion of the hydrolysis of starch by amylase
Then, we looked at the purpose and actions of the endocrine system, a system of glands that REGULATE/maintain homeostasis by causing relatively long-term or longer lasting changes (usually) in an organism as a result of signals/changes/cues from the environment (internal or external).
We saw that each gland secretes specific hormones directly into the bloodstream; each hormone can only bind to specific "target cells" that the hormone is made for. For example, insulin, secreted by the pancreas, can bind to specific cells in the liver because the protein receptors on those liver cells match the particular shape (lock and key) of the insulin hormone.

Once the hormone binds to the target cells, the target cells will produce particular chemicals or enzymes that helps the body to maintain homeostasis.

We saw that the pituitary gland, which is the master gland because it targets/controls all but one of the other endocrine glands, is directed/controlled by the hypothalamus. The hypothalamus is the nexus or connection between the nervous system, which is always sensing/monitoring the environmental changes of an organism, and the endocrine system.
The hypothalamus has many different cell receptors so it is able to monitor the levels of many of the body's key biochemicals and the hypothalamus will send a hormone/chemical signal to the pituitary if/when any of those biochemicals are in too high or too low a concentration.
The pituitary will then secrete the appropriate hormone so that the appropriate target cells/gland will secrete a substance to maintain homeostasis i.e. raise or lower the level of the deficient or excess chemical.
We then looked at the thyroid gland, which regulates the body's respiratory rate/metabolic rate.
The parathyroid glands, embedded in the four corners of the thyroid gland, regulate the level of calcium ions in the blood and bones.
We also began to discuss the all IMPORTANT concept of negative FEEDBACK, which is THE key feature of maintaining homeostasis.
For example, if the level of calcium ions in the blood is too low, the parathyroid glands will secrete a hormone (parathormone) that targets the BONE CELLS to release some of their stored calcium ions into the blood, thus RAISING the level of calcium ions back to a normal level. Once the normal level of calcium ions is back to normal (this is the "feedback" part!), that normal level of calcium ions in the blood CAUSES the parathyroid glands to STOP secreting its hormone (parathormone). That completes the feedback cycle and calcium homeostasis is maintained.
adrenals- adrenaline is secreted when a person is under high stress from the environment (internal or external) and causes a relatively quick increase in blood glucose, blood pressure, and overall metabolic rate so that the person can effectively fight or flee the situation.
adrenal glands also secrete hormones that regulate the concentration of water and sodium ions in the blood by targeting kidney cells.
We discussed the sex hormones secreted from the ovaries (females) and testes (males):
the menstrual cycle, involving the periodic thickening of the uterus and the maturation and release of an egg cell is regulated by pituitary hormones and ovary hormones (estrogen and progesterone); also, secondary sex characteristics develop as a result of the secretion of sex hormones: in females, breast development and skeletal changes such as the broadening of the pelvis occur; in males, testosterone causes more facial and body hair to grow and/or thicken, muscles to develop, the larynx to become thicker and more developed (deeper voice).

We then focused on the all-important negative feedback loop:
negative feedback is a key feature of the endocrine system that helps an organism maintain homeostasis. In general,
a deficiency of some substance "X" is monitored and detected by some gland "G"--> the gland then secretes a hormone "H" which targets specific cells which then are signaled to make more of substance "X" (increasing the level of substance "X" in the blood) so that there is no more deficiency; (now for the NEGATIVE feedback part) the normal/increased level of substance "X" in the blood causes gland "G" to STOP secreting hormone "H" (otherwise the level of substance "X" may get TOO HIGH!) thus completing the feedback loop and maintaining homeostasis.

Bio 7/8- we looked at the purpose and actions of the endocrine system, a system of glands that REGULATE/maintain homeostasis by causing relatively long-term or longer lasting changes (usually) in an organism as a result of signals/changes/cues from the environment (internal or external).
We saw that each gland secretes specific hormones directly into the bloodstream; each hormone can only bind to specific "target cells" that the hormone is made for. For example, insulin, secreted by the pancreas, can bind to specific cells in the liver because the protein receptors on those liver cells match the particular shape (lock and key) of the insulin hormone.

Once the hormone binds to the target cells, the target cells will produce particular chemicals or enzymes that helps the body to maintain homeostasis.

We saw that the pituitary gland, which is the master gland because it targets/controls all but one of the other endocrine glands, is directed/controlled by the hypothalamus. The hypothalamus is the nexus or connection between the nervous system, which is always sensing/monitoring the environmental changes of an organism, and the endocrine system.
The hypothalamus has many different cell receptors so it is able to monitor the levels of many of the body's key biochemicals and the hypothalamus will send a hormone/chemical signal to the pituitary if/when any of those biochemicals are in too high or too low a concentration.
The pituitary will then secrete the appropriate hormone so that the appropriate target cells/gland will secrete a substance to maintain homeostasis i.e. raise or lower the level of the deficient or excess chemical.
We then looked at the thyroid gland, which regulates the body's respiratory rate/metabolic rate.
The parathyroid glands, embedded in the four corners of the thyroid gland, regulate the level of calcium ions in the blood and bones.
We also began to discuss the all IMPORTANT concept of negative FEEDBACK, which is THE key feature of maintaining homeostasis.
For example, if the level of calcium ions in the blood is too low, the parathyroid glands will secrete a hormone (parathormone) that targets the BONE CELLS to release some of their stored calcium ions into the blood, thus RAISING the level of calcium ions back to a normal level. Once the normal level of calcium ions is back to normal (this is the "feedback" part!), that normal level of calcium ions in the blood CAUSES the parathyroid glands to STOP secreting its hormone (parathormone). That completes the feedback cycle and calcium homeostasis is maintained.
adrenals- adrenaline is secreted when a person is under high stress from the environment (internal or external) and causes a relatively quick increase in blood glucose, blood pressure, and overall metabolic rate so that the person can effectively fight or flee the situation.
adrenal glands also secrete hormones that regulate the concentration of water and sodium ions in the blood by targeting kidney cells.
We discussed the sex hormones secreted from the ovaries (females) and testes (males):
the menstrual cycle, involving the periodic thickening of the uterus and the maturation and release of an egg cell is regulated by pituitary hormones and ovary hormones (estrogen and progesterone); also, secondary sex characteristics develop as a result of the secretion of sex hormones: in females, breast development and skeletal changes such as the broadening of the pelvis occur; in males, testosterone causes more facial and body hair to grow and/or thicken, muscles to develop, the larynx to become thicker and more developed (deeper voice).

We then focused on the all-important negative feedback loop:
negative feedback is a key feature of the endocrine system that helps an organism maintain homeostasis. In general,
a deficiency of some substance "X" is monitored and detected by some gland "G"--> the gland then secretes a hormone "H" which targets specific cells which then are signaled to make more of substance "X" (increasing the level of substance "X" in the blood) so that there is no more deficiency; (now for the NEGATIVE feedback part) the normal/increased level of substance "X" in the blood causes gland "G" to STOP secreting hormone "H" (otherwise the level of substance "X" may get TOO HIGH!) thus completing the feedback loop and maintaining homeostasis.

AP Chem- we had our test on most of the colligative properties as well as metal-ligand complex naming and Born-Haber Hess Diagrams; quite a potpourri!

Bio 6/7- we discussed the life process of regulation as directed by the nervous system (shorter term coordination) and the endocrine system (longer term coordination). We discussed the function of each of the major glands and the important mechanism of hormonal "feedback" loops.
The endocrine system is a system of 9 glands: hypothalamus, pituitary, pineal, thymus, thyroid, parathyroid, adrenal, islets of Langerhans (of the pancreas), testes (male), ovaries (female).
These glands secrete substances DIRECTLY into the bloodstream for quick circulation throughout the body, HOWEVER, only one SPECIFIC group of "target cells" can bind to a given specific hormone. The target cells will then produce a substance or substances that will help the body maintain homeostasis. The glands are then signalled to stop secreting the hormone once homeostasis is reached (this is known as a negative feedback loop).
Specifically, we looked at the purpose and actions of the endocrine system, a system of glands that REGULATE/maintain homeostasis by causing relatively long-term or longer lasting changes (usually) in an organism as a result of signals/changes/cues from the environment (internal or external).
We saw that each gland secretes specific hormones directly into the bloodstream; each hormone can only bind to specific "target cells" that the hormone is made for. For example, insulin, secreted by the pancreas, can bind to specific cells in the liver because the protein receptors on those liver cells match the particular shape (lock and key) of the insulin hormone.

Once the hormone binds to the target cells, the target cells will produce particular chemicals or enzymes that helps the body to maintain homeostasis.

We saw that the pituitary gland, which is the master gland because it targets/controls all but one of the other endocrine glands, is directed/controlled by the hypothalamus. The hypothalamus is the nexus or connection between the nervous system, which is always sensing/monitoring the environmental changes of an organism, and the endocrine system.
The hypothalamus has many different cell receptors so it is able to monitor the levels of many of the body's key biochemicals and the hypothalamus will send a hormone/chemical signal to the pituitary if/when any of those biochemicals are in too high or too low a concentration.
The pituitary will then secrete the appropriate hormone so that the appropriate target cells/gland will secrete a substance to maintain homeostasis i.e. raise or lower the level of the deficient or excess chemical.
We then looked at the thyroid gland, which regulates the body's respiratory rate/metabolic rate.
The parathyroid glands, embedded in the four corners of the thyroid gland, regulate the level of calcium ions in the blood and bones.
We also began to discuss the all IMPORTANT concept of negative FEEDBACK, which is THE key feature of maintaining homeostasis.
For example, if the level of calcium ions in the blood is too low, the parathyroid glands will secrete a hormone (parathormone) that targets the BONE CELLS to release some of their stored calcium ions into the blood, thus RAISING the level of calcium ions back to a normal level. Once the normal level of calcium ions is back to normal (this is the "feedback" part!), that normal level of calcium ions in the blood CAUSES the parathyroid glands to STOP secreting its hormone (parathormone). That completes the feedback cycle and calcium homeostasis is maintained.
We then finished our discussion of the salivary amylase enzyme lab.

Bio 8- we discussed the life process of regulation as directed by the nervous system (shorter term coordination) and the endocrine system (longer term coordination). We discussed the function of each of the major glands and the important mechanism of hormonal "feedback" loops.
The endocrine system is mainly a system of 9 glands: hypothalamus, pituitary, pineal, thymus, thyroid, parathyroid, adrenal, islets of Langerhans (of the pancreas), testes (male), ovaries (female).
These glands secrete substances DIRECTLY into the bloodstream for quick circulation throughout the body, HOWEVER, only one SPECIFIC group of "target cells" can bind to a given specific hormone. The target cells will then produce a substance or substances that will help the body maintain homeostasis. The glands are then signalled to stop secreting the hormone once homeostasis is reached (this is known as a negative feedback loop).
Specifically, we looked at the purpose and actions of the endocrine system, a system of glands that REGULATE/maintain homeostasis by causing relatively long-term or longer lasting changes (usually) in an organism as a result of signals/changes/cues from the environment (internal or external).
We saw that each gland secretes specific hormones directly into the bloodstream; each hormone can only bind to specific "target cells" that the hormone is made for. For example, insulin, secreted by the pancreas, can bind to specific cells in the liver because the protein receptors on those liver cells match the particular shape (lock and key) of the insulin hormone.

Once the hormone binds to the target cells, the target cells will produce particular chemicals or enzymes that helps the body to maintain homeostasis.

We saw that the pituitary gland, which is the master gland because it targets/controls all but one of the other endocrine glands, is directed/controlled by the hypothalamus. The hypothalamus is the nexus or connection between the nervous system, which is always sensing/monitoring the environmental changes of an organism, and the endocrine system.
The hypothalamus has many different cell receptors so it is able to monitor the levels of many of the body's key biochemicals and the hypothalamus will send a hormone/chemical signal to the pituitary if/when any of those biochemicals are in too high or too low a concentration.
The pituitary will then secrete the appropriate hormone so that the appropriate target cells/gland will secrete a substance to maintain homeostasis i.e. raise or lower the level of the deficient or excess chemical.
We then looked at the thyroid gland, which regulates the body's respiratory rate/metabolic rate.
The parathyroid glands, embedded in the four corners of the thyroid gland, regulate the level of calcium ions in the blood and bones.
We also began to discuss the all IMPORTANT concept of negative FEEDBACK, which is THE key feature of maintaining homeostasis.
For example, if the level of calcium ions in the blood is too low, the parathyroid glands will secrete a hormone (parathormone) that targets the BONE CELLS to release some of their stored calcium ions into the blood, thus RAISING the level of calcium ions back to a normal level. Once the normal level of calcium ions is back to normal (this is the "feedback" part!), that normal level of calcium ions in the blood CAUSES the parathyroid glands to STOP secreting its hormone (parathormone). That completes the feedback cycle and calcium homeostasis is maintained.

AP Chem- tomorrow we have our exam on the vacation assignment material as well as on Hess Diagrams for the Born-Haber Cycle.
The exam covers the colligative properties of boiling point elevation, freezing point depression, and osmotic pressure; it also covers naming and formula writing of metal-ligand complexes (usually but not always involving transition metals) and, finally, the Hess Law problems and diagrams with which physicists and chemists calculate lattice energy, heat of formation, etc.

Today, we looked at the main cause of colligative properties, entropy, and its effect on lowering vapor pressure of a solvent as a solution forms by dissolving a solute in the solvent. As long as the dissolving solute is non-volatile (does not easily vaporize), then Raoult's Law is obeyed for solutions that behave "ideally" (more on that later this unit).
We saw that Raoult's Law is similar in form to Dalton's Law of Partial Pressures for gases.

We then reviewed a bit for tomorrow's exam. I have extra help in the AM for last minute questions. There are plenty of practice questions on Blackboard.

Bio 6- we reviewed the purposes of the major nutrients and then did a review worksheet on nutrition and the digestive system. We must start the endocrine system tomorrow.

Bio 7/8- we discussed disorders/diseases of the digestive system and went over the purposes of the major nutrients. We then did a review worksheet on nutrition and the digestive system. We must start the endocrine system tomorrow.
We did a lab using indicators to show the effect of salivary amylase on the starch contained in pretzels.

AP Chem- we did two colligative property problems, one involving freezing point depression and the other involving osmotic pressure. If you have forgotten how to get empirical formulas from percent composition (this is a BASIC AP chem skill that you must know intuitively by now), make sure that you review the process (and units involved) and the reasoning behind it (ALL formulas show the MOLE RATIOS (NEVER the MASS ratios) of the atoms or ions in the compound).
IMPORTANT NOTES:
even if you are given a POSITIVE freezing point depression constant on the AP exam (which is illogical), make sure that you change its sign to NEGATIVE (as in DEPRESSION).
Reminder, delta T is ALWAYS final Temp minus initial Temp, in that order!
You will ALWAYS get a NEGATIVE delta T value for freezing point DEPRESSION problems; if you do not, you did something wrong and you will lose points ESPECIALLY if you make the double error of using a positive freezing point depression constant to get the "right" answer.
To get the proper "i", van t' Hoff factor values, you must know whether a compound is an electrolyte or a nonelectroyte (or weak electrolyte). ALL molecules EXCEPT for STRONG ACIDS do not ionize significantly or at all so they have an i = 1 value; for other compounds, you must count the number of ions per formula unit of the salt or hydroxide base or you will use an
i = 2 value for any strong acid.

We then reviewed the Born-Haber cycle in order to determine the heat of formation of a salt or its lattice energy. We saw that for cations that have a charge greater than +1, you will need or be given multiple ionization energy values; we also saw that for ANIONS that have a charge more NEGATIVE than -1, you will need or be given multiple ELECTRON AFFINITY values, which typically get progressively more POSITIVE (endothermic) because you are trying to add an (negative) electron to an already created (negative) ANION.
I put up a practice worksheet for more exercise with these problems.

Bio 6/7- we covered five different ailments/diseases of parts of the digestive system, their causes and symptoms.
We then discussed the two different types of nutrition and the special advantageous adaptations that certain organisms have for their particular type of nutrition e.g. green algae have chloroplasts in order to perform photosynthesis/autotrophic nutrition.
We then reviewed the function of the major nutrients.
We did a lab using indicators to show the effect of salivary amylase on the starch contained in pretzels.

Bio 8- we covered five different ailments/diseases of parts of the digestive system, their causes and symptoms.
We then discussed the two different types of nutrition and the special advantageous adaptations that certain organisms have for their particular type of nutrition e.g. green algae have chloroplasts in order to perform photosynthesis/autotrophic nutrition.

Happy 2009 to you all! I treated myself to a B'berry so now I can more conveniently update this blog at all times of the day or night. Ah technology, making life easier and harder at the same time.

AP Chem- The ANNOTATED answer key to the vacation assignment is now posted on Blackboard. Note the extensive use and DESIGNATION of units WITH attribution to either the solvent or solute; this is a BIG DEAL. Use and PROPER cancellation of units will HEAVILY influence your grade on Thursday's exam. For each question you MUST
1. Write the applicable formula
2. REARRANGE the applicable formula (unless you are starting with the isolated requested variable on one side of the equation) so that you are solving for what is requested
3. Plug in the properly labeled data WITH units.
4. After that, the problem solves itself! If you make a calculator error at this point, assuming the first three steps are correct, you will not lose more than one or two points (probably just one point unless your answer is ridiculous) out of ten or fifteen.
Today we began our review of the vacation assignment.
Points noted:
in transition metal complex ANIONS, ONLY the transition metal name gets the suffix ATE;
oftentimes, you will end up writing two vowels in a row e.g. hexaaqua or tetraammine;
transition metal complexes form BECAUSE there are d orbitals that are close in energy to the valence principal energy level s and p orbitals, which hybridize to form 6 empty d2sp3 or 5 empty dsp3 orbitals that overlap to form coordinate covalent sigma bonds with the lone pairs of electrons in orbitals from the ligand molecules or ions.

We then rearranged the freezing point depression or boiling point elevation formulas to directly solve for the molar mass of the solute. The final formula shows proper unit cancellation and ends up with units of grams per mole. Try to cancel the units and see how the formula works because you will have to do this on Thursday's exam.

Molar mass of solute = ( k x i x grams of solute) divided by ( delta T x kg of solvent)

Bio 6- we reviewed the digestive structure and function of the small intestine, its accessory organs (liver and pancreas), and the large intestine/colon. We reviewed the results of digestion for each major nutrient (carbs, lipids, proteins, and nucleic acids) and the enzymes involved in the digestion/hydrolysis of each nutrient.
We are almost done with all of the nutrition/digestion objectives so we can transition to the regulation/endocrine system part of this unit.

Bio 7/8- we reviewed the digestive structure and function of the small intestine, its accessory organs (liver and pancreas), and the large intestine/colon. We reviewed the results of digestion for each major nutrient (carbs, lipids, proteins, and nucleic acids) and the enzymes involved in the digestion/hydrolysis of each nutrient.
We are almost done with all of the nutrition/digestion objectives so we can transition to the regulation/endocrine system part of this unit.
We finished the writeup/data part of the antagonistic muscle group lab. I'll grade that sometime this week; remind me on Friday if you do not see your grade, thank you.