SciHawks

Bio - we discussed the circulatory/respiratory system activity that we performed on Thursday. We particularly focused on the changes in blood composition that occur in the lungs and around body tissues due to diffusion of O2 and CO2 in and out of the capillaries at these locations.
We also discussed the threat to homeostasis that occurs when a person is bleeding internally or externally and how the body deals with this threat.

AP Chem - we saw how the "order"/molecularity of a reaction, for each reactant, is calculated using the graphs from kinetics data. We can then write the correct "experimentally determined" RATE LAW for that reaction and also determine the RATE CONSTANT for that reaction at a particular temperature.
We carefully noted the UNITS of the rate constant for EACH or 0th, 1st, 2nd, and even 3rd order reactions.
We then related the experimentally determined rate law to the actual number of molecules that are colliding in the RATE DETERMINING (slow) step of a reaction.
We saw how to propose a reaction MECHANISM that is CONSISTENT with an experimentally determined rate law for a given reaction. The mechanism must have a slow/rate determining step that yields the same rate law as that determined experimentally, AND also the mechanism's elementary steps MUST add up to the NET reaction.

We then saw how, when a mechanism has a fast equilibrium step, followed by a slow step, we may have to substitute for the intermediate formed to see whether a rate law is actually consistent with the experimentally determined rate law.

AP Chem- we reviewed reaction rates and their expressions and reviewed the meaning of the fraction that shows "rate of change" of a given substance.
We discussed chemical reaction mechanisms in terms of order, molecularity, and probability of multiple-molecule collisions.
We related the raw rate data to the graphs of concentration vs. time. Then, taking data from several different concentration vs. time graphs for a given reaction, we saw the plot of INITIAL RATE vs. INITIAL CONCENTRATION in order to determine the "order" of the reaction with respect to a given reactant. The "order" of the reaction (the exponent given to the substance to make the initial rate vs. initial concentration graph a STRAIGHT LINE) indicated the NUMBER of those reactant molecules involved in collisions in the slowest/rate determining step of the reaction mechanism.
See Blackboard for further tutorials.

AP Chem - we discussed how and why each factor that CAN affect the rate of a reaction actually AFFECTS the reaction. We discussed "nature" of the reactant, catalysts, concentration, temperature, and (for solids and liquids) surface area.
We then reviewed the measurements and calculations of rates of reactions and the relative rates of disappearance of reactants to the rates of appearance of products. You must know how to relate one to the other and how to relate BOTH to the standard for calculating the rate of "the reaction", overall.

Bio 3/6 - we reviewed the three general regions of circulation: pulmonary (to lungs), systemic (to just about anywhere else in the body), and coronary (to the heart).
We discussed blood pressure and the meaning of the systolic (ventricles SQUEEZE) and the diastolic blood pressure numbers as measured by a sphygmomanometer.

We then discussed diseases that cause failure to maintain homeostasis in the circulatory system:
general cardiovascular diseases
hypertension/high blood pressure
coronary thrombosis (complete blockage) of the coronary arteries - leads to heart attack
angina pectoris (partial blockage i.e. narrowing) of the coronary arteries - leads to heart attack

AP Chem - we dissected and applied the equation to get a rate of reaction from the rate of appearance of any product or the rate of disappearance of any reactant, by using the balanced equation.
We then solved for the rate of appearance of any given product GIVEN the rate of disappearance of any reactant or the rate of appearance of any other product.

We briefly introduced the factors that affect the RATE of a given reaction.

Bio 3/6 - we discussed the THREE "regions" of the human circulatory system:
PULMONARY, SYSTEMIC, and CORONARY circulation.
Pulmonary circulation allows for the exchange of gases between the blood in the capillaries around the lung air sacs ("alveoli") and the air sacs themselves; carbon dioxide diffuses out of the blood and into the air sacs to be exhaled while oxygen that was inhaled diffuses from the air sacs into the blood.
Systemic circulation allows for the diffusion of the transported oxygen from the blood in the capillaries to any given body cell (nerve, muscle, hair follicle, liver) while carbon dioxide diffuses from any given body cell into the blood in the capillaries.
Coronary circulation is the transport of oxygenated blood FROM the HEART back TO the HEART, which has a constant and high demand for oxygen so that it can perform AEROBIC respiration to produce the ATP that provides the ENERGY for heart muscle contractions 24/7 (heartbeats).

AP Chem - we took the test that is the culmination and synthesis of the units on atomic structure, periodicity, bonding, molecular geometry, and finally intermolecular attractions. If you got anything wrong on this test, MAKE SURE to ask about it and go over it with me at extra help. You CANNOT do well on the AP exam without confident and accurate knowledge of the aforementioned topics.
We continue with our second semester tomorrow as we delve further into KINETICS.
Check Blackboard for the current notes on that unit.

Bio 3/6- we carefully examined the sequence, structure, and various changes that occur in the blood as it goes through the "cardiac cycle"/heart cycle to the lung capillaries and to all of the capillary "beds" throughout the body.
Please review and study the animation of the cardiac cycle that is posted on Blackboard.

We discussed the parts of the human transport system, in general: the pump/heart, the fluid/blood, and the tubes/arteries, veins, and capillaries.

We contrasted the structure and function of arteries, veins, and capillaries and noted the special features of each.

AP Chem-  check Blackboard for a practice exam (no answer key; email or come to extra help if you would like an opinion on the sufficiency/quality of your written responses!) related to Monday's exam. The questions on the exam cover some but not ALL of the questions that will appear on Monday's exam (the rest of the question types are covered in the previously posted files and notes).

In general, on Monday's exam, make sure that you know in detail:

- how to draw the correct Lewis structure for any molecule
- how to determine hybridization, electronic geometry, molecular geometry, bond polarity, molecular polarity, and the resulting intermolecular force(s) of attraction for each molecule; also relate the IMFA's to physical properties such as boiling point, and vapor pressure at a given temperature.
- know the relative strengths of each IMFA and the reason(s) for the relative strengths
- know the explanation of why "like dissolves like" down to the molecular level and the related explanation of how ionic substances are either soluble or insoluble in a polar solvent
- know how to construct a phase diagram from basic data (as in notes) and deduce phase changes, relative phase densities, etc.
- know the different types of solids and the explanation of the IMFA's or BONDS involved in each type
- know all of the descriptive chemistry reactions that we have done all week and how to write their balanced net ionic equations including phase labels

- there are NO questions on this exam from our new unit on Kinetics (we just started that!).

Bio 3/6 - we began our unit on Transport, Respiration, and Excretion via the Circulatory, Respiratory, and Excretory systems, respectively.
We did an activity in which, from your previous knowledge, you drew out and explained the structure and function of the human heart. We used this as a starting point to compare and contrast what you previously knew to what, in our higher level course, we will learn/modify/correct about the heart.

AP Chem- we drew out several Lewis structures and examined the electronic and molecular geometry, the bond polarity, and then the molecular polarity of each.
We related the molecular polarity to the type and degree of intermolecular forces of attraction and then to the physical properties such as vapor pressure at room temperature and also to normal boiling point.

Bio 3/6 - took our unit exam on the digestive and endocrine systems. We then discussed some previous labs and the forthcoming unit on the circulatory, respiratory, and excretory systems.

AP Chem - we explained the physical properties of water and dihydrogen monosulfide by drawing their respective Lewis structures, discussing the molecular geometry and bond polarity of each molecule, and seeing the source of their molecular polarities.
We then continued to answer some questions regarding IMFA's.
We will finish this unit tomorrow and then start our first, second semester unit: Kinetics!

Bio 3/6 - Mrs. Friedman has generously offered extra help EARLY tomorrow (Wednesday), 7:15 AM to 8:10 AM in Room 302 (adjacent to our classroom). I had extra help this morning, which was attended by one student. The time to ask about what you are unsure of is before a test; you can ask afterwards also, but that is after you have lost points on your test. 

We practiced for tomorrow's exam by reviewing a typical example of regulation via a negative feedback mechanism involving glands and hormones of the endocrine system.
We also discussed the four major macronutrients, their digestive end-products (see today's notes or your hw), the location of their digestion, and the enzymes involved.


Practice writing/DRAWING/EXPLAINING the major objectives from your hw so that, on tomorrow's test, you can more easily explain regulation and nutrition.

AP Chem- we did another descriptive chem set, with some improvement observed - sometime very soon, we should ALL be able to solve these questions in about two minutes.
We focused on intermolecular attractions, how to deduce them and their relative degrees by drawing out the Lewis structure of the molecule and inferring from the electronic and molecular geometry, whether a dipole existed or did not exist.

AP Chem - we continued to work on phase diagrams as we discussed the typical questions about them.
There are plenty of practice tests/worksheets and tutorials on Blackboard to practice for your next test on IMFA's, bonding, solid types, and descriptive chem.

AP Chem - we did another descriptive chem problem set and then we discussed intermolecular forces of attraction. The degree and type of attraction depends on
1. the "polarizability" of the molecule i.e. the number of electrons in the molecule that can be randomly shifted to one "side" of the molecule or another.
2. the degree of a permanent dipole (if any) that exists in the molecule, which is based on the degree of ASYMMETRIC distribution of electrons, which is based on molecular geometry and electronegativity differences between the bonded atoms.

AP Chem - we discussed ion-dipole attractions, which typically occur when an ionic compound/salt dissolves in a polar solvent/water. We then looked at the source of dipoles and dipole-dipole attraction.

AP Chem- took the unit exam on transition metal complexes and colligative properties and Raoult's Law.
Please, somebody remind me tomorrow to discuss the Chemistry Olympiad competition. I think that our class/Jericho could decimate the national competition (because we know all about the cause of EVERYTHING: Zeff and OPEL's)
:)

Bio 3/6 - we finished disorders of the digestive tract by discussing the causes, mechanism, and effects of diarrhea (too little water reabsorption from colon into blood) and constipation (too much water reabsorption from colon into blood).

We discussed the life process of regulation as controlled by the endocrine system (the nervous system is also a key regulatory system) via a system of glands that secrete hormones that affect specific target cells.
We did an example of how your hypothalamus, pituitary, and thyroid glands work together to maintain metabolic/respiratory homeostasis.

We finished our discussion of the salivary amylase digestion of starch lab.

AP Chem- we did the first of many daily descriptive chemistry review sheets.
We then discussed phase diagrams, how to interpret them and decipher such data as the triple point, the critical point, the normal boiling and freezing points, and whether the solid or liquid phase is denser.

As for tomorrow's test on the vacation assignment/colligative properties/Raoult's Law, expect questions on the following subtopics:

transition metal-ligand complex naming and formulas as well as writing a balanced equation for metal-ligand complex formation.

electron configurations of transition metal ions

colligative properties of solutions of non-electrolytes, weak electrolytes (e.g. weak acids), and strong electrolytes (e.g. soluble salts) with respect to freezing point depression, boiling point elevation, and osmotic pressure elevation in every permutation of the formulas including the determination of the molar mass of the solute.

application of Raoult's Law and Dalton's Law in determining the mole fractions of solvent and solute in the liquid phase and in the vapor phase.

application of Raoult's Law in determining the vapor pressure lowering effect of adding a solute to a solvent and in determining the molar mass of a solute

inferring the relative solute-solute, solute-solvent, and solvent-solvent degrees of attraction given a positive or negative deviation from Raoult's Law and drawing this result graphically.

AP Chem - We discussed two types of Raoult's Law graphs: one plots vapor pressure vs. mole fraction in the liquid phase of a two-component mixture and the other plots temperature/boiling points vs. mole fraction in the liquid phase (the lower curve) as well as the vapor phase (the upper curve). 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 different mole fractions between the vapor phase and liquid phase mixture (as in a distillation column/apparatus) that are in equilibrium (as seen by a horizontal line at a given boiling point; the vapor phase mixture that an increased mole fraction of the component that has weaker intermolecular forces. When this vapor phase mixture is then condensed and cooled further (vertical line down) to a liquid mixture, the weaker IMFA component is increased in proportion in that mixture.

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 sp3, sp3d, or sp3d2 orbitals ACCEPTS a lone pair of electrons from the ligand to form a coordinate covalent bond, the pair of electrons from the ligand now sandwiched between the positive nuclei of the ligand and of the transition metal.
We will go over writing the descriptive chem answers and strategies for this type of reaction. We noted that the number of ligands that bind to a given transition metal ion of charge "n+"  is 2 times "n".

Bio 3/6- we developed a "master chart" showing each part of the digestive tract/tube (the "alimentary canal"), its main function in digestion (chemical and/or mechanical), the accessory organs - pancreas and liver- and their functions, as well as the macronutrients (larger nutrient molecules) digested and the end-products/small simple molecules that are formed from the nutrient digestion in each part of the digestive system.
We did a starch digestion lab in which we used iodine solution as the starch indicator; ideally, we showed that starch is present in pretzels (the iodine solution turns blue-black when it reacts with starch) and flour but when the flour or pretzels are mixed with amylase enzyme from saliva, the starch gets broken down so that when iodine is added, no blue-black color appears (the test is negative for starch).

AP Chem - we derived yet another shortcut formula for getting the molar mass of a solute from Raoult's Law data. The IMPORTANT thing to keep track of is the TYPE (solute or solvent) and PHASE of EACH substance used in the MOLE FRACTION data. In our shortcut formula, we use the mole fraction of each component in the LIQUID PHASE!
We then saw and discussed the source and measurement of vapor pressure and analyzed a series of vapor pressure curves.
Check Blackboard for more practice problems and solutions.

Bio 3/6- we reviewed a worksheet to reinforce the knowledge of the specific functions of each part of the digestive system with respect to the enzymes produced and the specific nutrients digested.

AP Chem -  We focused on Raoult's Law and did several problems in which we used vapor pressure and mole fraction of substances IN SOLUTION to make calculations with respect to vapor pressure lowering and also with respect to molar mass of the solute.
We also showed that, once the partial pressures of all vapor components are calculated via Raoult's Law, we could THEN use Dalton's Law to calculate the mole fraction of each component in the GAS/VAPOR phase.
We also confirmed, based on predictions of intermolecular forces and the actual vapor pressure data, which of the components of a mixture should INCREASE in its mole fraction in the VAPOR/GAS phase relative to its mole fraction in the LIQUID phase (i.e. the component(s) with WEAKER IMFA's will INCREASE in their mole fraction in the vapor phase because a GREATER fraction of its molecules will have sufficient energy to overcome these WEAKER IMFA's and "escape" into the vapor/gas phase.

Bio 3/6 - we discussed autotrophic and heterotrophic nutrition, the three distinct processes involved in nutrition (ingestion, digestion, egestion), and the two types of cellular digestion (intra and extra).

AP Chem - we discussed and applied the various formulas for colligative properties of solutions: freezing point depression, boiling point elevation, and osmotic pressure elevation.
We re-arranged the formulas so that we can calculate the most common/practical quantity inferred by these properties: the molar mass of an unknown solute.
We looked at the similarities and differences between Dalton's Laws and Raoult's Law and saw that, typically, both laws are used in problems involving vapor pressure calculations.

We're back in business! It's tough getting back but we'll be in the groove very soon.


Bio 3/6 - eased back in to schoolwork with our Locomotion/Regulation unit test review. Each test is an opportunity to advance your test-taking skills by seeing how applying these techniques make the tests easier and your answers of higher quality and value.
We will cover the digestive system in its entirety in the next few days.

AP Chem- we covered a couple of questions from the vacation assignment and then we rearranged some of the colligative property equations, putting them into a more practical form.
We discussed the basis/cause of colligative properties of solutions, which depend solely on the concentration of dissolved solute particles in solution.
There is a LOT of material on Blackboard with even more to come for further practice so make use of that.