Preparation
Forces and Bonding: Gases

Name:

Section:

1. This experiment.
2. The appropriate or assigned sections of your textbook.

1. A plastic syringe is weighed empty and is found to have a mass of 35.6978 g. The syringe is filled to the 50-mL mark with an unknown gas, then reweighed. The new mass is 35.7743 g. Assuming atmospheric pressure to be 700 torr and room temperature to be 20 ^oC, what is the molar mass of the gas? What is the gas?
2. On a day when atmospheric pressure is 730 torr and room temperature is 20 ^oC, a plastic syringe with an inside cross-sectional area of 1 in² is filled to the 50-mL mark with helium gas. The syringe plunger is pushed against a bathroom scale until the volume of the gas has been decreased to 30 mL. Assuming ideal conditions, what is the scale reading in pounds?
3. When 0.0350 g of a gas is put into a plastic syringe at 720 torr and 25 ^oC, the gas occupies a volume of 45.4 mL. When 0.0280 g of the gas is removed from the syringe, what volume will be occupied by the remaining gas?