Monday, December 04, 2006
Monday
Honors: we just about finished the Periodic Table Unit. Notes for our new unit, the heart of chemistry, the all-important "Chemical Bonding" unit, will be posted tonight.
Note: in the Orange Review Book, questions regarding the formulas of compounds and oxidation states won't be covered or tested on Wednesday's test.
Note 2: this is a GOOD one: thanks to our Marisa for bringing up, at extra help, a question from the last multiple choice test. As we discussed the answers, it became apparent that two of the answers were possible or at least arguably close calls. Bring in your tests tomorrow and I will check whether you have one of the two correct answers. The class average is going up! Good times.
It also became apparent how many students had misgrids on this test. Up to this test, I have allowed misgrids to be corrected but that will not be the case on tests for at least the near future. I aim to discourage careless gridding so you are going to eat the lost points, if you misgrid on upcoming tests.
The end of the Periodic Table consists of physical and chemical characteristics of the various groups of elements. Memorization is key; any of these minute but practical facts can and will be tested on the Regents and SAT II exams.
In the review book hw from this past weekend, there is some information about oxidation numbers and compound formulas. Don't worry about those things for now. We will cover them in the next unit.
Regents: we calculated the empirical formulas of many salts and then we reversed the process and went from the name of the compound to what must be the empirical formula of the compound. We also did test review.
Tomorrow, we will start with the empirical formula of a compound, predict the name, and find the charge on the respective cation and anion.
AP: we did examples of structures that had various bond orders and bond lengths. As bond order increases, bond strength increases BUT bond length decreases. The more pairs of electrons that are shared between two positive nuclei, the greater the NET force of attraction between the two bonded atoms, thus the shorter the bond length.
We further practiced resonance structures and calculated bond order by dividing the total number of bonds between the different atoms by the number of "bonding regions/domains" between the different atoms.
We explained the phenomenon of "smog" on a warm day and clear yet polluted skies on a cool day by showing the dimerization of nitrogen dioxide to dinitrogen tetroxide. We discussed Le Chatelier's Principle and the thermodynamics of bond formation (exothermic) and bond breakage (endothermic) and related the rates of the forward and reverse reactions to increasing or decreasing temperatures.
Tomorrow, we cover the last material before our next test. This extended weekend, we will cover the transition metal complex topic in the text. You will quickly become expert at naming transition metal complexes and the reactions that form them.
Note: in the Orange Review Book, questions regarding the formulas of compounds and oxidation states won't be covered or tested on Wednesday's test.
Note 2: this is a GOOD one: thanks to our Marisa for bringing up, at extra help, a question from the last multiple choice test. As we discussed the answers, it became apparent that two of the answers were possible or at least arguably close calls. Bring in your tests tomorrow and I will check whether you have one of the two correct answers. The class average is going up! Good times.
It also became apparent how many students had misgrids on this test. Up to this test, I have allowed misgrids to be corrected but that will not be the case on tests for at least the near future. I aim to discourage careless gridding so you are going to eat the lost points, if you misgrid on upcoming tests.
The end of the Periodic Table consists of physical and chemical characteristics of the various groups of elements. Memorization is key; any of these minute but practical facts can and will be tested on the Regents and SAT II exams.
In the review book hw from this past weekend, there is some information about oxidation numbers and compound formulas. Don't worry about those things for now. We will cover them in the next unit.
Regents: we calculated the empirical formulas of many salts and then we reversed the process and went from the name of the compound to what must be the empirical formula of the compound. We also did test review.
Tomorrow, we will start with the empirical formula of a compound, predict the name, and find the charge on the respective cation and anion.
AP: we did examples of structures that had various bond orders and bond lengths. As bond order increases, bond strength increases BUT bond length decreases. The more pairs of electrons that are shared between two positive nuclei, the greater the NET force of attraction between the two bonded atoms, thus the shorter the bond length.
We further practiced resonance structures and calculated bond order by dividing the total number of bonds between the different atoms by the number of "bonding regions/domains" between the different atoms.
We explained the phenomenon of "smog" on a warm day and clear yet polluted skies on a cool day by showing the dimerization of nitrogen dioxide to dinitrogen tetroxide. We discussed Le Chatelier's Principle and the thermodynamics of bond formation (exothermic) and bond breakage (endothermic) and related the rates of the forward and reverse reactions to increasing or decreasing temperatures.
Tomorrow, we cover the last material before our next test. This extended weekend, we will cover the transition metal complex topic in the text. You will quickly become expert at naming transition metal complexes and the reactions that form them.
# posted by C @ 9:18 AM 
