Friday, October 24, 2008
Fri-Day 1
AP Chem- I have posted a plethora of practice tests complete with detailed answers. If you do these tests and understand the methods and answers, Thursdays test will be a breeze for you. So that you have time to do these practice tests and peruse the notes and study guide, I am only assigning a few Ch. 4 text questions to be handed in next Tuesday (along with the one or two questions from Ch.3, if you did not complete them all previously).
Chapter 4 HW questions: 16, 24, 30, 36, 42, 54, 58, 62, 64
We finished the double-replacement (ALL double replacements are NON-redox reactions so do NOT bother with the half-reaction method for them) stoichiometry problem in which we determine the volume of acid required to completely react with the sulfide salt. ALL acid + sulfide salt reactions produce gaseous dihydrogen sulfide gas!
We then did a redox titration stoichiometry problem totally from scratch, just using the NAMES of the reactants and products and balancing the reaction by using the half-reaction method. We identified the oxidizer and the reducing agent and then we applied the MOLE RATIOS from the BALANCED equation (as we will always do). From the data, we determined the percentage of iron (as 2+ ions) in a sample of iron ore.
We then began another double replacement (with precipitation) problem from scratch, which we will develop further on Monday. In this problem, we will focus on the mass of precipitate formed as well as the concentrations of all dissolved ions that remain in solution.
We continued our lab prep for the titration of the hypochlorite ion in bleach. You learned how to condition a buret so that the titrant is not diluted by water droplets that may have been inside the buret. You weighed out potassium iodide, which will form a complex with starch to be used as an indicator for the redox reaction. Some of you did not label (as instructed) your weighing dishes so you will have to start that part again.
Bio 6/7- we further discussed and labelled the structure/components of DNA. We have begun to see/draw out the mechanism by which a DNA molecule can replicate into two exact copies of the original molecule.
We further discussed the required State Lab on osmosis and diffusion through a cell membrane; we used the results of the indicator tests to make deductions and conclusions regarding which substances diffused through the cellulose membrane that we made.
Bio 8-we further discussed and labelled the structure/components of DNA. We have begun to see/draw out the mechanism by which a DNA molecule can replicate into two exact copies of the original molecule.
Chapter 4 HW questions: 16, 24, 30, 36, 42, 54, 58, 62, 64
We finished the double-replacement (ALL double replacements are NON-redox reactions so do NOT bother with the half-reaction method for them) stoichiometry problem in which we determine the volume of acid required to completely react with the sulfide salt. ALL acid + sulfide salt reactions produce gaseous dihydrogen sulfide gas!
We then did a redox titration stoichiometry problem totally from scratch, just using the NAMES of the reactants and products and balancing the reaction by using the half-reaction method. We identified the oxidizer and the reducing agent and then we applied the MOLE RATIOS from the BALANCED equation (as we will always do). From the data, we determined the percentage of iron (as 2+ ions) in a sample of iron ore.
We then began another double replacement (with precipitation) problem from scratch, which we will develop further on Monday. In this problem, we will focus on the mass of precipitate formed as well as the concentrations of all dissolved ions that remain in solution.
We continued our lab prep for the titration of the hypochlorite ion in bleach. You learned how to condition a buret so that the titrant is not diluted by water droplets that may have been inside the buret. You weighed out potassium iodide, which will form a complex with starch to be used as an indicator for the redox reaction. Some of you did not label (as instructed) your weighing dishes so you will have to start that part again.
Bio 6/7- we further discussed and labelled the structure/components of DNA. We have begun to see/draw out the mechanism by which a DNA molecule can replicate into two exact copies of the original molecule.
We further discussed the required State Lab on osmosis and diffusion through a cell membrane; we used the results of the indicator tests to make deductions and conclusions regarding which substances diffused through the cellulose membrane that we made.
Bio 8-we further discussed and labelled the structure/components of DNA. We have begun to see/draw out the mechanism by which a DNA molecule can replicate into two exact copies of the original molecule.
# posted by C @ 11:20 AM 
