AP CHEM Unit 11 Days 01-02

A gas has a volume of 2.00 liters at a temperature of 127◦C. What will be the volume of the gas if the temperature is increased to 327◦C? (Assume the pressure remains constant.)

• 2.00 liters

• 3.00 liters

• 4.00 liters

• 6.00 liters

For a substance that remains a gas under the conditions listed, deviation from the Ideal Gas Law would be most pronounced at

• 100◦C and 2.0 atm.

• −100◦C and 2.0 atm.

• −100◦C and 4.0 atm.

• 100◦C and 4.0 atm.

A sealed container has a measured pressure of 5.00 atm. The gas contains 0.200 mol Helium, 0.050 mol Argon, and 0.250 mol Krypton.  What would be the partial pressure of the heaviest gas?

• 0.250 atm

• 0.050 atm

• 0.200 atm

• 2.50 atm

A steel tank containing helium is heated from 300◦C  to 555◦C. If you could look into the tank and see the gas molecules, what would you observe?

• The gas molecules would have higher kinetic energies and lower velocities, thus creating no net change.

• The gas molecules would have lower kinetic energies and higher velocities, thus creating no net change.

• The gas molecules would have lower velocities and lower kinetic energies and move in straight lines until hitting the walls of the tank.

• The gas molecules would have higher velocities and higher kinetic energies and move in straight lines until hitting the walls of the tank.

Each sealed syringe contains 10mL of a different noble gas at standard temperature.  The gases are then injected into a previously evacuated 50mL Erlenmeyer flask.  What is the total pressure of the gases in the Erlenmeyer flask at standard temperature?

• 1.2atm

• 12atm

• 2.4atm

• 60atm

Rank the following gases in order of increasing non-ideality due to intermolecular interactions:

• HCl < CF₄ < N₂ < He

• He < N₂ < CF₄ < HCl

• CF₄ < HCl < N₂ < He

• He < N₂ < HCl < CF₄

Which statement is FALSE?

• The molecules of an ideal gas are relatively very far apart on the average.

• The molecules of a gas move in straight paths until they collide with other molecules or the walls of their containers, according to the kinetic molecular theory.

• The average kinetic energies of molecules of samples of different ideal gases at the same temperature are the same.

• At a given temperature, according to kinetic molecular theory, the average velocity of He molecules is less than the average velocity of F₂ molecules.

You are told that 2.55 g of a gaseous hydrocarbon occupies a vessel of volume 3.0 L at 0.95 atm and 82◦C.  What is the molar mass of the gas?

• 
• 
• 
• 

At constant temperature if the volume of a gas sample is tripled the pressure will

• be one third the original.

• remain the same.

• be tripled.

• be increased by a factor of 6.

When the actual gas volume is greater than the volume predicted by the ideal gas law, the explanation lies in the fact that the ideal gas law does NOT include a factor for molecular

• volume.

• mass.

• kinetic energy.

• attractions.