CHEM 120 Week 8 Lab Practical Review

1. Question: You are given the following pH values: Solution 1: 9.2, Solution 2: 4.8, Solution 3: 12.7, Solution 4: 1.1 a. Which solutions are basic? b. Which solution would have the highest concentration of H3O+ ions when dissolved in water? 2. Question: You are given three compounds: NaCl, CH3CH2OH (ethanol), and CaCl2. You are asked to measure out 14.7 g of each compound into three separate 500-mL flasks and add enough water to make 500-mL of solution. A chemist comes along and measures the conductivity of each of the solutions and find that both the NaCl and CaCl2 solutions are highly conductive and the ethanol solution isn’t conductive at all. Answer the following questions. a. Using your knowledge of the compound structures, bond types, and conductivity results, which compounds are ionic and which are not? b. Determine the percent concentration of the three solutions. c. What are the names of the two ionic compounds used in the experiment? 3. Question: You are given the structure of an organic molecule (right): a. What is the name of the compound shown and what is the functional group? b. What is the condensed structure for the compound above? c. What type of bond exists between C and H and between O and H? 4. Question: It is an unseasonably warm day in late November where the temperature reached a surprising 80 oF in Vail, CO (elevation 8500 ft). To celebrate, you decide to have your child’s birthday party in the backyard and tape really fancy balloons to your mailbox and front door. The next morning, you forgot that the balloons were left out overnight and the temperature dropped below freezing. Answer the following questions. a. When you go out to retrieve your balloons, what do you expect to see? b. What do you think could happen if you filled a balloon to the bursting point in the city of Denver and drove it to Vail, CO? 5. Question: Chromium-51 (51Cr) has a half-life of 30 days and decays by electron capture. Answer the following questions. a. What is the decay product of 51Cr? b. If you had 100 g of Cr-51 initially, how many grams would you have after 90 days? 6. Question: Balance the following chemical reaction: Ca3(PO4)2 + MgO == CaO + Mg3(PO4)2