1. Determine the empirical formula of a compound containing 47.37 grams of carbon, 10.59 grams of hydrogen, and 42.04 grams of oxygen.
In an experiment, the molar mass of the compound was determined to be 228.276 g/mol. What is the molecular formula of the compound?
For both questions, show your work or explain how you determined the formulas by giving specific values used in calculations.
2 A chemist reacted 11.50 grams of sodium metal with an excess amount of chlorine gas. The chemical reaction that occurred is shown.
Na + Cl2 → NaCl
If the percentage yield of the reaction is 85%, what is the actual yield? Show your work including, the use of stoichiometric calculations and conversion factors.
3. Compare the compressibility of gases and liquids. Support your answer by describing the arrangement of particles in gases and liquids.
4. Two glasses labeled A and B contain equal amounts of water at different temperatures. Kim put an antacid tablet into each of the two glasses. The table shows the time taken by the tablet to dissolve completely in the two glasses.
| Antacid Experiment | |
| Glass | Time |
| A | 40 seconds |
| B | 10 seconds |
Which of the following statements is correct?
5. Part 1. A lightly inflated balloon is placed in a freezer. Explain the change to the size of the balloon based on the kinetic molecular theory.
Part 2. What would most likely happen to the balloon if it was instead kept outside in the sun for some time? Explain your answer based on the kinetic molecular theory.
In both cases, assume the balloon is tied tight enough so that air does not escape.
6. Part 1. A chemist reacted 18.0 liters of F2 gas with NaCl in the laboratory to form Cl2 gas and NaF. Use the ideal gas law equation to determine the mass of NaCl that reacted with F2 at 290. K and 1.5 atm.
F2 + 2NaCl → Cl2 + 2NaF
Part 2. Explain how you would determine the mass of sodium chloride that can react with the same volume of fluorine gas at STP.
