Tuesday, March 17, 2009
Tues-Day 1
AP Chem- two days until buffer/titration test day- use the posted practice worksheets/tests/tutorials! You MUST see similar questions on Thursday's test! No tricks!
Speaking of no tricks, today's descriptive chem quiz was written exactly as described and the substances chosen were relatively easy and common.
We finished the titration of weak base by strong acid problem involving the common points of interest. We then discussed acid-base indicators, noting that these indicators are actually colored weak acids that have conjugate bases of a different color! Thus, we only use a drop or two of indicator so as not to significantly affect the pH of the titration solution.
We saw how to choose a suitable/viable indicator for a given titration by looking for an indicator pKa that is within ONE UNIT of the expected equivalence point pH; this way, the indicator will be in the middle of a color change at the equivalence/end point of the titration.
We then discussed the major features of a polyprotic acid titration curve (titrated by a weak base).
Tomorrow, we begin our next-to-penultimate topic on slightly soluble salts.
Bio 6/7 - NOTE: omit objectives 14-17 in your homework because we did not significantly discuss those answers yet in class. Also, you can PREVIEW the reproduction video from PBS at this link.
We discussed the chromosomal mutation of NONDISJUNCTION that can occur during either anaphase I or anaphase II of meiosis. This meiosis "mistake" usually results in gametes that have one MORE or one LESS chromosome than the normal haploid number of chromosomes.
If these gametes fertilize an egg (or are fertilized) the resulting zygote/embryo is either not viable (won't live) or it will develop abnormally.
We briefly discussed embryonic development and will continue with that tomorrow.
We then did a meiosis lab simulation with gummy worms, showing the results of meiosis I and meiosis II with and without nondisjunction.
Bio 8- We discussed the chromosomal mutation of NONDISJUNCTION that can occur during either anaphase I or anaphase II of meiosis. This meiosis "mistake" usually results in gametes that have one MORE or one LESS chromosome than the normal haploid number of chromosomes.
If these gametes fertilize an egg (or are fertilized) the resulting zygote/embryo is either not viable (won't live) or it will develop abnormally.
We briefly discussed embryonic development and will continue with that tomorrow.
Speaking of no tricks, today's descriptive chem quiz was written exactly as described and the substances chosen were relatively easy and common.
We finished the titration of weak base by strong acid problem involving the common points of interest. We then discussed acid-base indicators, noting that these indicators are actually colored weak acids that have conjugate bases of a different color! Thus, we only use a drop or two of indicator so as not to significantly affect the pH of the titration solution.
We saw how to choose a suitable/viable indicator for a given titration by looking for an indicator pKa that is within ONE UNIT of the expected equivalence point pH; this way, the indicator will be in the middle of a color change at the equivalence/end point of the titration.
We then discussed the major features of a polyprotic acid titration curve (titrated by a weak base).
Tomorrow, we begin our next-to-penultimate topic on slightly soluble salts.
Bio 6/7 - NOTE: omit objectives 14-17 in your homework because we did not significantly discuss those answers yet in class. Also, you can PREVIEW the reproduction video from PBS at this link.
We discussed the chromosomal mutation of NONDISJUNCTION that can occur during either anaphase I or anaphase II of meiosis. This meiosis "mistake" usually results in gametes that have one MORE or one LESS chromosome than the normal haploid number of chromosomes.
If these gametes fertilize an egg (or are fertilized) the resulting zygote/embryo is either not viable (won't live) or it will develop abnormally.
We briefly discussed embryonic development and will continue with that tomorrow.
We then did a meiosis lab simulation with gummy worms, showing the results of meiosis I and meiosis II with and without nondisjunction.
Bio 8- We discussed the chromosomal mutation of NONDISJUNCTION that can occur during either anaphase I or anaphase II of meiosis. This meiosis "mistake" usually results in gametes that have one MORE or one LESS chromosome than the normal haploid number of chromosomes.
If these gametes fertilize an egg (or are fertilized) the resulting zygote/embryo is either not viable (won't live) or it will develop abnormally.
We briefly discussed embryonic development and will continue with that tomorrow.
# posted by C @ 10:43 AM 
