GAS LAWS AND STOICHIOMETRY: How MUCH ALUMINUM IS IN A SODA CAN? PRELAB ASSIGNMENT 1. Statement of Purpose: Write a purpose statement that addresses the following questions: What is the purpose of having you do this experiment? What techniques will you learn? What chemical theories will you study/apply in the experiment? How, generally, will you perform the experiment? 2. Hazards: Identify any specific chemicals or laboratory techniques that could be hazardous when performing this experiment and how you will exercise caution in handling/performing them. 3. Why is it important to cut the aluminum can sample into small pieces? 4. Why is it necessary to equalize water levels in the buret and the leveling funnel before reading the buret volume? 5. To how many decimal places should a buret volume reading be recorded? 6. Explain why the hydrogen gas collected in the experiment is referred to as "wet" hydrogen gas. 7. What is the vapor pressure of water at 21C ? 8. A 0.0198-g sample taken from an aluminum can was allowed to react with excess 6MHCl and the hydrogen gas produced was collected (over water) in a buret. The volume of the sample was measured after equalizing the water levels in the buret and a leveling funnel. The gas sample had a temperature of 21.0C and a volume of 25.83mL, and the atmospheric pressure in the laboratory was 733.6mmHg. (a) Calculate the pressure of the "dry" hydrogen. (b) Determine the amount of hydrogen (in moles) collected. (c) Calculate the percentage, by mass, of aluminum in the original sample of aluminum can