Chapter 4 Test Review

Below are images of a solutions guide to the optional practice exam. Remember, the pdf file for the Chapter 4 test review can be found on the AP Chemistry calendar. I changed the review since I made the key, so problem #15 is different. The bottom image is the solution to number 15.
You will be given all equations needed for the test. You will be able to use your periodic table. You will not be supplied with the solubility rules. If you remember the basic solubility rules, an assumption can be made that anything that does not fit a basic solubility rule is not soluble, thus a solid. The test is 20 multiple choice questions. Do not think that you do not have to do the work to solve a problem. Just looking at the answers will not suffice.