Week of 10/12

Monday: No school – Columbus Day

Tuesday: Today we went over gravimetric analysis (see videos on unit 2 page if you missed them or need help).  I showed you how vacuum filtration works and we did the lab based problem on page 22 of the packet.  This is actually the answer, but we just covered up the answer and went through the problem on a separate sheet of paper. The rest of class you worked on other gravimetric analysis problems 4.83, 4.85, 4.87.

Wednesday: No class cuz you were all taking the PSATs

Thursday: Today we started by going over the terms saturated, unsaturated, soluble, insoluble and partially soluble – and drew pictures for them. The key to showing the difference between saturated and unsaturated is to know the solubility limit of the compound.  If there’s a lower molarity than the solubility limit = unsaturated, if = molarity to solubility limit = saturated.  Saturated solutions are easy to detect if enough has been mixed that a precipitate has formed.   Then we worked on practice problems in the packet – pages 15 and 16.  3 answers on page 16 are wrong on the key (key is on page 23).  The net ionic reaction for #9, 10 and 11 should have the solids in them since solids are included in net ionic reactions.  When I wrote the answer key I wrote the net ionic rxns as if they solids were aqueous. So here’s the answer for number 12) Fe(HCO3)3 + 3H+(aq) –> 3H2O(l) + 3CO2(g) + Fe3+(aq)

Homework: Neutralization problems: 4.31, 89, 91, 93 and rest of gravimetric analysis problems: 4.115, 4.117, 4.119

Friday: Today we are going to start with page 19 in your packet…multiple reactions and mole ratios! It turns out that you can string mole ratios from one reaction to another reaction, you can multiply reactions times a coefficient and you can add reactions together.Then your goal is to write procedures for a lab…here’s the premise: I am going to give you a sample of an alkali metal carbonate – basically a white powder that you know has a carbonate ion and an alkali metal ion, but you don’t know which alkali metal it is.  Your goal is to figure out which alkali metal it is.  As a group you will write procedures that will both explain the procedures and the calculations behind the procedures.  You will do the lab on Monday and hopefully have enough time to do the calculations. Homework will be to write a conclusion.  Grades will be: Data Collection, Experimental methods (grade based on procedures and evaluation of procedures), and Math.  Notes and lab instructions.