Friday, March 30, 2012
Fri-Day 2
AP Chem - we did a mixture of ions problem in which we determined whether a precipitate formed.
If a precipitated did form, we proceeded to determine whether there was "complete" (99% or more) precipitation of the insoluble salt from solution. We also detemine the mass of the precipitate formed.
Bio - We related Mendel's Law of Dominance to the expression of alleles (translation to proteins, and their effect on phenotype) and Law of Segregation (of hereditary factors) to anaphase, telophase, and cytokinesis that occurs during meiosis/gamete formation.
We looked at the phenotypes and genotypes as represented in organizers/Punnett squares, so that we can predict ratios of different phenotypes and genotypes of offspring of given parents.
If a precipitated did form, we proceeded to determine whether there was "complete" (99% or more) precipitation of the insoluble salt from solution. We also detemine the mass of the precipitate formed.
Bio - We related Mendel's Law of Dominance to the expression of alleles (translation to proteins, and their effect on phenotype) and Law of Segregation (of hereditary factors) to anaphase, telophase, and cytokinesis that occurs during meiosis/gamete formation.
We looked at the phenotypes and genotypes as represented in organizers/Punnett squares, so that we can predict ratios of different phenotypes and genotypes of offspring of given parents.
# posted by C @ 11:39 AM 
Thursday, March 29, 2012
Thurs-Day 1
AP Chem - we showed that we cannot compare the molar solubilities of different general formula (MX, MX2, etc.) salts merely by comparing their respective Ksp values.
We quantitatively demonstrated the "common ion" effect, showing the decrease in solubility of a given salt in a solution containing ONE common ion of the salt.
Bio - we detailed Mendel's experiments and related his inferences about "hereditary factors" to what we now know about alleles and the process of making gametes via meiosis.
We quantitatively demonstrated the "common ion" effect, showing the decrease in solubility of a given salt in a solution containing ONE common ion of the salt.
Bio - we detailed Mendel's experiments and related his inferences about "hereditary factors" to what we now know about alleles and the process of making gametes via meiosis.
# posted by C @ 11:20 AM
Wednesday, March 28, 2012
Wednes-Day 2
AP Chem - Unit exam on acid/base/buffer equilibria tomorrow; this is our THIRD test in a row on equilibrium.
Review all notes; re-write all examples until you understand the logic of the problem-solving process!
Do as many practice problems as is necessary to be confident in doing any problem type!
Questions types covered:
we determined the magnitude of the solubility "suppression" of a given salt in a solution containing a common ion of that given salt.
We then determined "will a precipitate form?" by determining and comparing the value of Qsp to Ksp.
If precipitation occurs after mixing of two aqueous solutions, we then use SRFC and ICE organizers to determine the percent precipitation of a given ion, and the number of grams of precipitate formed at equilibrium.
This is not easy; there are many pitfalls in these problems, as you experienced today! Repeated practice and daily review are required.
Bio - we began our new unit on Modern Genetics by discussing the experiments of Mendel, how they were fair, logical i.e. scientific, and led to a discovery of the patterns of inheritance i.e. the Laws of Inhertance.
Review all notes; re-write all examples until you understand the logic of the problem-solving process!
Do as many practice problems as is necessary to be confident in doing any problem type!
Questions types covered:
- how to make a buffer including choosing the correct quantities of appropriate salts, acids, and bases to produced a solution of a desired pH.
- quantitatively determining the effect of adding a given quantity of strong acid or base to either a buffer, or to a weak base or weak acid, respectively
- the above requires knowledge of when and when not to use the H-H equation, and the assumption built into any practical use of that equation i.e. initial = equilibrium concentrations.
- qualitatively and quantitatively assess each of the four types of titration curves, knowing the relative concentrations of conjugates at each point, determining pKa's , pKb's from the graph.
- quantititatively determining the concentration of any species in solution at any point in any titration of a weak acid or base, and sketching the accompanying curve; also determining Ka, Kb, pKa, pKb from titration curve data or pH measurements at particular points of the titration.
- choosing an appropriate acid-base indicator that will change color at/near the equivalence point of a given titration, and explaining quantitatively and qualitatively how that is the appropriate choice
- drawing and analyzing the titration curve of a polyprotic acid titrated by a strong base
- I will separately test Lewis acids/bases on a future descriptive chem quiz.
we determined the magnitude of the solubility "suppression" of a given salt in a solution containing a common ion of that given salt.
We then determined "will a precipitate form?" by determining and comparing the value of Qsp to Ksp.
If precipitation occurs after mixing of two aqueous solutions, we then use SRFC and ICE organizers to determine the percent precipitation of a given ion, and the number of grams of precipitate formed at equilibrium.
This is not easy; there are many pitfalls in these problems, as you experienced today! Repeated practice and daily review are required.
Bio - we began our new unit on Modern Genetics by discussing the experiments of Mendel, how they were fair, logical i.e. scientific, and led to a discovery of the patterns of inheritance i.e. the Laws of Inhertance.
# posted by C @ 10:37 AM
Tues-Day 1
AP Chem - we determined how to calculate the molar solubility of a single salt in aqueous solution, and then we quantitatively determined the molar solubility of the same salt in a aqueous solution of a salt that contains a cation or anion in common with the given salt.
We saw that, kinetically, the presence of the common ion causes a greater rate of precipitation than of dissolving, thus, the molar solubility of the given salt is lower/depressed in a solution of its common ion.
Bio - took the unit exam on Sexual Reproduction.
We saw that, kinetically, the presence of the common ion causes a greater rate of precipitation than of dissolving, thus, the molar solubility of the given salt is lower/depressed in a solution of its common ion.
Bio - took the unit exam on Sexual Reproduction.
# posted by C @ 8:42 AM
Monday, March 26, 2012
Mon-Day 2
AP Chem- we strictly defined the solubility of a salt, and the molar solubility, s, of a salt, and then related that to the concentrations of its aqueous ions in a saturated/at equilibrium solution; from that, we determine the Ksp value of the salt at a given temperature.
We also did a kinetic stress to gauge the effect on Ksp.
Bio - reviewed for tomorrows exam, as we focused on embryonic development, as well as a discussion of the meiosis/gummy worm manipulation lab.
Check Edline for HW answers.
We also did a kinetic stress to gauge the effect on Ksp.
Bio - reviewed for tomorrows exam, as we focused on embryonic development, as well as a discussion of the meiosis/gummy worm manipulation lab.
Check Edline for HW answers.
# posted by C @ 6:56 PM
Friday, March 23, 2012
Fri-Day 1
AP Chem - we finished our acid base equilibria unit by analyzing polyprotic acid titration curves in every way.
We then used this information to determine how to make a buffer from various available salts of the amphoteric ions from a polyprotic acid.
We then introduced the new unit on Ksp, sparingly soluble salt equilibria.
Bio - we focused on embryonic development, especially the exchange of nutrients and wastes between mother and baby via the placenta.
You may omit the following HW objectives as you complete your HW this weekend; it is due on Monday.
The unit exam is on Tuesday.
- #6 "in vitro fertilization" is the fertilization of an egg by sperm in a container/test tube; this is the alternative to "in vivo" fertilization via sexual intercourse.
# 21. describe the major mechanisms (how and where) of reproduction and development in vertebrates.
all other objectives are explicitly covered in our notes.
We then used this information to determine how to make a buffer from various available salts of the amphoteric ions from a polyprotic acid.
We then introduced the new unit on Ksp, sparingly soluble salt equilibria.
Bio - we focused on embryonic development, especially the exchange of nutrients and wastes between mother and baby via the placenta.
You may omit the following HW objectives as you complete your HW this weekend; it is due on Monday.
The unit exam is on Tuesday.
- #6 "in vitro fertilization" is the fertilization of an egg by sperm in a container/test tube; this is the alternative to "in vivo" fertilization via sexual intercourse.
# 21. describe the major mechanisms (how and where) of reproduction and development in vertebrates.
all other objectives are explicitly covered in our notes.
# posted by C @ 6:37 PM
Thursday, March 22, 2012
Thurs-Day 2
AP Chem - we finished a slightly tricky titration data problem in which the data points did not come from nice, neat equivalence points or halfway to them.
We then introduced polyprotic acid titration curves.
Bio - we finished our analysis of the production of gametes via meiosis (i.e. oogenesis and spermatogenesis).
We emphasized the three sources of genetic variation/genetic recombination that occurs from meiosis.
We then introduced polyprotic acid titration curves.
Bio - we finished our analysis of the production of gametes via meiosis (i.e. oogenesis and spermatogenesis).
We emphasized the three sources of genetic variation/genetic recombination that occurs from meiosis.
# posted by C @ 6:26 PM
Wednesday, March 21, 2012
Wednes-Day 1
AP Chem - we finished the second permutation of a titration of a weak acid by a strong base; we looked at the common points of interest, this time determining the pKa of the acid from the titration "halfway to the equivalence point" data.
We then saw the same types of calculations for a titration of a weak base (pyridine) by a strong acid.
We then discussed acid-base indicators, which themselves are weak acids, thus just a few drops are used so that these weak acids do not significantly affect the pH of the solutions that they are indicating.
We saw how to determine an appropriate indicator for a given equivalence point pH; the indicator must have a pKa within one unit of the equivalence point pH so that the indicator will be in its buffer range thus showing an intermediate color of its acid and anion forms.
Bio - we went through each of the phases of meiosis, showing the important events in each phase.
You should practice drawing these from scratch, so that you can see when the cells become haploid from diploid, and when the three causes of genetic variety occur.
We then saw the same types of calculations for a titration of a weak base (pyridine) by a strong acid.
We then discussed acid-base indicators, which themselves are weak acids, thus just a few drops are used so that these weak acids do not significantly affect the pH of the solutions that they are indicating.
We saw how to determine an appropriate indicator for a given equivalence point pH; the indicator must have a pKa within one unit of the equivalence point pH so that the indicator will be in its buffer range thus showing an intermediate color of its acid and anion forms.
Bio - we went through each of the phases of meiosis, showing the important events in each phase.
You should practice drawing these from scratch, so that you can see when the cells become haploid from diploid, and when the three causes of genetic variety occur.
# posted by C @ 8:00 PM
Tuesday, March 20, 2012
Tues-Day 2
AP Chem- we began another permutation of a titration of a weak acid by a strong base, noting that the given info will always lead to the desired information.
Bio - we looked at animations of the meiosis process, and continued work on the female reproductive cycle lab.
Bio - we looked at animations of the meiosis process, and continued work on the female reproductive cycle lab.
# posted by C @ 8:00 PM
Monday, March 19, 2012
Mon-Day 1
AP Chem - We looked at the distinguishing features of each of the four possible titration curves.
We saw how to set up a titration, discussed "standardization" of a titrant, and then did each of the major steps of a titration of a weak acid by a strong base. We noted the part of the titration curve formed at each step of our calculation.
Note: for each step, we went back to the ORIGINAL solution, not to the previous step; this prevents unnecessary confusion in our organizers, which start with NOTHING on the product side.
Bio : we discussed the events of embyronic development that occur after pregnancy is established. We noted the structure and function of the placenta, which stems from some embryonic cells, and is the organ through which ALL nutrients (BUT NO BLOOD!!) diffuses to the baby from the mother, and through which all wastes diffuse from the baby to the mother. We also discussed the stages of the embryo from blastula to gastrula, and noted what each of the three germ cell layers of the gastrual turn into in a mature individual.
We saw how to set up a titration, discussed "standardization" of a titrant, and then did each of the major steps of a titration of a weak acid by a strong base. We noted the part of the titration curve formed at each step of our calculation.
Note: for each step, we went back to the ORIGINAL solution, not to the previous step; this prevents unnecessary confusion in our organizers, which start with NOTHING on the product side.
Bio : we discussed the events of embyronic development that occur after pregnancy is established. We noted the structure and function of the placenta, which stems from some embryonic cells, and is the organ through which ALL nutrients (BUT NO BLOOD!!) diffuses to the baby from the mother, and through which all wastes diffuse from the baby to the mother. We also discussed the stages of the embryo from blastula to gastrula, and noted what each of the three germ cell layers of the gastrual turn into in a mature individual.
# posted by C @ 8:02 PM
Wednesday, March 14, 2012
Wednes-Day 2
AP Chem - we did an acid buffer problem with the initial conditions of the conjugates in separate beakers containing different volumes and molarities of conjugates. In these cases, you must calculate the initial concentrations of the conjugates, which are diluted relative to before they were mixed, due to the greater new solution volume. Then you must check that the concentrations are in the buffer ratio range or 1/10 to 10/1.
We then looked at the derivation of the base version of the H-H equation starting with a generic Kb expression. We then applied the equation to a basic buffer problem.
We also discussed the maximum and minimum buffer pH for a given pair of conjugates.
Bio - we looked at the structures and functions of the various parts of the female reproductive system.
We then began our first look at the hormonal feedback mechanisms that control/regulate the female reproductive cycle.
We then looked at the derivation of the base version of the H-H equation starting with a generic Kb expression. We then applied the equation to a basic buffer problem.
We also discussed the maximum and minimum buffer pH for a given pair of conjugates.
Bio - we looked at the structures and functions of the various parts of the female reproductive system.
We then began our first look at the hormonal feedback mechanisms that control/regulate the female reproductive cycle.
# posted by C @ 1:39 PM
Tuesday, March 13, 2012
Tues-Day 1
AP Chem - took the unit exam on acids, bases, and salts.
Bio - we finished our description and analysis of the male reproductive system, and then began to look at the structure and function of the female reproductive system.
Bio - we finished our description and analysis of the male reproductive system, and then began to look at the structure and function of the female reproductive system.
# posted by C @ 6:07 PM
Monday, March 12, 2012
Mon-Day 2
AP Chem- tomorrow is the unit exam on acids and bases, and acid/base/salt equilibrium.
Today, we reviewed some Lewis acid info.
We then showed the derivation, and proper use of the Henderson-Hasselbalch equation, which is used for convenience when there is a BUFFER CONDITION. Given that condition, we make the safe assumption that the equilibrium acid and base conjugate concentrations are almost equal to their initial buffer concentrations.
Bio - we reviewed the various evolutionary advantages and disadvantages of sexually reproducing species.
We then focused on the structures and functions of the various parts of the male reproductive system, and how they are advantageous in fostering reproduction.
Today, we reviewed some Lewis acid info.
We then showed the derivation, and proper use of the Henderson-Hasselbalch equation, which is used for convenience when there is a BUFFER CONDITION. Given that condition, we make the safe assumption that the equilibrium acid and base conjugate concentrations are almost equal to their initial buffer concentrations.
Bio - we reviewed the various evolutionary advantages and disadvantages of sexually reproducing species.
We then focused on the structures and functions of the various parts of the male reproductive system, and how they are advantageous in fostering reproduction.
# posted by C @ 7:46 AM
Friday, March 9, 2012
Fri-Day 1
AP Chem - we analyzed Lewis acids and bases; Lewis acids are typically Boron compounds (electron-"deficient species") or high-charge density metal ligand complexes; we saw that it is actually the water ligand of the metal ligand complex that reacts with adjacent water molecules, as an H+ from the water ligand accepts an electron pair from the adjacent water's oxygen, thus forming hydronium ion in solution, thus making the solution acidic, lowering the pH.
We also showed four ways to make a buffer solution that will effectively neutralize significant quantities of added acid or base without a subsequently significant change in pH.
Bio - began the unit on sexual reproduction. Earlier in the course, we discussed various forms of asexual reproduction, chiefly involving some type of mitosis and cytokinesis.
We discussed the evolutionary advantages of sexually reproducing species (variety/diversity improves probability of the species survival in a changing environment, as well as some disadvantages (energy required to find a mate, and actually mate).
We also showed four ways to make a buffer solution that will effectively neutralize significant quantities of added acid or base without a subsequently significant change in pH.
Bio - began the unit on sexual reproduction. Earlier in the course, we discussed various forms of asexual reproduction, chiefly involving some type of mitosis and cytokinesis.
We discussed the evolutionary advantages of sexually reproducing species (variety/diversity improves probability of the species survival in a changing environment, as well as some disadvantages (energy required to find a mate, and actually mate).
# posted by C @ 11:03 AM
Thursday, March 8, 2012
Thurs-Day 2
AP Chem - we did two more salt pH, pKa, pKb, % ionization problems, going through the various permutations of knowns and unknowns; typically, these questions will use a little bait-and-switch: for basic salts, the Ka or pKa of the conjugate acid of the basic anion is usually given, for acidic salts, the Kb or pKb of the conjugate base of the acidic cation is usually given.
Here is a preliminary list of question types for your test next Tuesday:
• sparingly soluble salt equilibrium shifts
due to stresses (explain via kinetics, predict via Le Chat)
•conjugate acid-base pairs and predicting the favored side of rxn as eq. is reached given Ka, Kb, values
• pH, pOH calculation for strong acids and bases
• explanation of acid strength via bond polarity
and bond strength and their causes (Zeff, etc.)
•weak acid eq, calcs pH, pKa,[HA]initial % ionization
•weak base eq pH, pOH, pKb, [B]initial, % ionization
•acidic ,basic salts
-causes/ reactions
•pH calcs of acid, basic salts BHX, MA
Bio - we took the unit exam on regulation via the nervous system.
Here is a preliminary list of question types for your test next Tuesday:
• sparingly soluble salt equilibrium shifts
due to stresses (explain via kinetics, predict via Le Chat)
•conjugate acid-base pairs and predicting the favored side of rxn as eq. is reached given Ka, Kb, values
• pH, pOH calculation for strong acids and bases
• explanation of acid strength via bond polarity
and bond strength and their causes (Zeff, etc.)
•weak acid eq, calcs pH, pKa,[HA]initial % ionization
•weak base eq pH, pOH, pKb, [B]initial, % ionization
•acidic ,basic salts
-causes/ reactions
•pH calcs of acid, basic salts BHX, MA
Bio - we took the unit exam on regulation via the nervous system.
# posted by C @ 8:18 AM
Wednesday, March 7, 2012
Wednes-Day 1
AP Chem - we discussed the causes of acidic, basic, and neutral salts, seeing that the ions that make up a salt are either inert in water (group 1 cations, strong acid conjugate base anions) or are actually weak Bronsted acids or bases that react with water to produce excess hydronium or hydroxide ions.
We wrote out these reactions, thus seeing the cause of the solution type.
We then did quantitative calculations of the pH of salt solutions containing either an acidic cation or a basic anion; for this we needed pK (a or b) information either directly of the ion in the salt OR of the ion's conjugate.
We also saw how to determine the slight acidity or basicity of a salt made of both a Bronsted acid cation and a Bronsted base anion.
Bio - we reviewed for tomorrow's exam by doing a detailed comprehensive explanation of nerve cell electrochemical communication to regulate the body i.e. to maintain homeostasis. See the remainder of the answer on Edline.
We wrote out these reactions, thus seeing the cause of the solution type.
We then did quantitative calculations of the pH of salt solutions containing either an acidic cation or a basic anion; for this we needed pK (a or b) information either directly of the ion in the salt OR of the ion's conjugate.
We also saw how to determine the slight acidity or basicity of a salt made of both a Bronsted acid cation and a Bronsted base anion.
Bio - we reviewed for tomorrow's exam by doing a detailed comprehensive explanation of nerve cell electrochemical communication to regulate the body i.e. to maintain homeostasis. See the remainder of the answer on Edline.
# posted by C @ 5:16 PM
Tuesday, March 6, 2012
Tues-Day 2
AP Chem -we did weak base equilibrium problems, showing the specific H+ accepting reaction common to all Bronsted bases; we went through the typical pKb, pH, percent ionization, and concentration calculations.
Bio - we discussed the different classifications of drugs i.e. analgesics, narcotics, stimulants, and depressants.
We looked at the effects of various drugs via either increased inhibition of the release of particular neurotransmitters or increased release of particular neurotransmitters.
We finished our discussion of the various diseases of the nervous system.
Bio - we discussed the different classifications of drugs i.e. analgesics, narcotics, stimulants, and depressants.
We looked at the effects of various drugs via either increased inhibition of the release of particular neurotransmitters or increased release of particular neurotransmitters.
We finished our discussion of the various diseases of the nervous system.
# posted by C @ 5:06 PM
Monday, March 5, 2012
Mon-Day 1
AP Chem - did a weak acid equilibrium calculation, determining the pH and percent ionization from given Ka and initial conditions; we examined the case when the percent ionization of the acid is not negligible relative to the initial acid concentration. This led to an examination of the percent ionization of a weak acid as the molarity of the acid decreases i.e. increasing dilution causes a shift that favors product formation i.e. the ionized products.
We then did another problem permutation in which Ka is determined given initial acid concentration and the resulting pH of the solution (at equilibrium).
We then did another problem permutation in which Ka is determined given initial acid concentration and the resulting pH of the solution (at equilibrium).
Bio- for HW objectives due tomorrow, you can omit 19-23 inclusive. We will discuss drugs and their effects tomorrow.
Today, we reviewed disorders and diseases of the nervous system. We also reviewed how the nervous system is classified by location or by function.# posted by C @ 6:43 PM
Thursday, March 1, 2012
Thurs-Day 1
AP Chem - we explained in detail the relative strengths of binary acids, down a group and also across a period (left to right), seeing the competing factors of bond strength and bond polarity.
We then compared the relative strengths of oxoacids for the three possible cases.
Explanations require proper Lewis structure drawings, proper use of Zeff on valence electrons and OPEL's/shells of electrons in explaining relative bond strength and bond polarity.
We then compared the relative strengths of oxoacids for the three possible cases.
Explanations require proper Lewis structure drawings, proper use of Zeff on valence electrons and OPEL's/shells of electrons in explaining relative bond strength and bond polarity.
Bio - we reviewed neuron structure and function, a reflex arc of a sneeze, and then we looked at the brain in terms of its three main parts (cerebrum, cerebellum, and medulla oblongatta) and their respective functions.
# posted by C @ 2:18 PM
