Gen Chem 1

Gas Laws including reaction stoichiometry and molar volume (STP)

1. 16mL of gas in a syringe at 1.0atm is taken to a depth where the volume compresses to 7.5mL. What is the pressure at this new depth?

2. A gas at an initial pressure of 547 mmHg and initial volume of 1.500L is compressed to a pressure of 723 mmHg. What is the new volume?

3. A gas sample with a volume of 178mL at 0.00^oC is heated until the volume is 225mL. What is the temperature at this new volume?

4. What is the pressure of 2.25g of nitrogen gas at a volume of 0.189L at 25^oC?

5. What is the density of a 0.85L sample of neon gas at 65^oC and 1.1atm?

6. A 1.25g sample of gas at 25^oC and 1.00atm has a volume of 663mL. What is the molar mass of the gas?

7. What volume (L) of hydrogen gas is formed from a complete reaction of 15.7 g solid carbon and excess gaseous water? (the products are carbon monoxide gas and hydrogen gas)

8. What volume of oxygen gas completely reacts with 45.8g of solid aluminum to form solid aluminum oxide? The vessel has a pressure of 782mmHg and a temperature of 25^oC.

9. 1.15g oxygen and 1.55g nitrogen gas combined at STP would occupy what volume?

Intermolecular Forces

1. Consider the compounds dimethylether (CH₃OCH₃), ethanol (CH₃CH₂OH), and propane (CH₃CH₂CH₃). Their boiling points, not necessarily in order, are −42.1 °C, −24.8 °C, and 78.4 °C. Match each compound with its boiling point. Explain your reasoning.

Phase Diagrams

1. Draw a heating curve with temperature on the y axis and heat added on the x axis. Label the following parts:

i. Solid, liquid, gas

ii. Melting, boiling, evaporation, condensation, freezing

(water phase diagram from OpenStax text inside the classroom) determine the state of water at the following temperatures and pressures:

1. −10 °C and 50 kPa

2. 25 °C and 90 kPa

3. 50 °C and 40 kPa

4. 80 °C and 5 kPa

5. −10 °C and 0.3 kPa

6. 50 °C and 0.3 kPa