Unit 5 - Gases

Michael and Abigail are observing a balloon filled with helium gas. Which statement describes the particles of the helium gas inside the balloon based on the kinetic molecular theory?

• Energy is not conserved during collisions between gas particles

• Particles move in constant, circular paths

• The volume of a gas particle is negligible compared to the volume the gas occupies

• The gas particles have strong, repulsive forces between them

Anika is conducting an experiment to study gas behavior. Under which conditions will the gas in her experiment behave most like an ideal gas?

• 50 K and 0.5 atm

• 50 K and 1.0 atm

• 250 K and 0.5 atm

• 250 K and 1.0 atm

Kai and Aiden are conducting an experiment with gases. According to Avogadro’s Hypothesis, if they have two separate samples of gases with the same volume, temperature, and pressure, these samples will also have

• The same number of molecules

• The same density

• The same color

• The same smell

Benjamin is conducting an experiment with a sealed container of gas. He observes changes in pressure, volume, and temperature. According to the combined gas law, which variable is assumed not to change from the initial to final conditions for the gas?

• Pressure

• Volume

• Temperature

• Moles of gas particles

Mia and Henry are comparing gas samples in their chemistry class. Which two gas samples contain equal numbers of atoms?

• Xe and CO₂

• Xe and H₂

• Kr and H₂

• CO₂ and Kr

Anika and Oliver are conducting an experiment in their chemistry class. They need to identify which particle model diagram represents H₂ (g) at STP. Can you help them choose the correct diagram?

• [Diagram 1]

• [Diagram 2]

• [Diagram 3]

• [Diagram 4]

Arjun is conducting an experiment with a sealed container that contains a gas with a pressure of 0.47 atm and a temperature of 485 K. What would the new pressure be if the temperature is increased to 687 K?

• 0.66 atm

• 0.75 atm

• 0.85 atm

• 0.95 atm

Abigail has a 286 mL balloon filled with gas at 100 °C. She cools it down to 24 °C. What is the new volume of the gas in liters? (3 pts)

• 0.214 L

• 0.250 L

• 0.286 L

• 0.300 L

Noah is conducting an experiment with a sample of gas at STP, which has a volume of 1.87 L. He reduces the pressure to 81.6 kPa. What is the new volume of the gas?

• 2.30 L

• 2.10 L

• 1.50 L

• 1.87 L

Abigail and Charlotte are conducting an experiment with two sealed, rigid cylinders with movable pistons. Each cylinder contains 500 mL of a gas sample at 101.3 kPa and 459 K. Cylinder A contains H₂(g) and cylinder B contains N₂(g). Compare the mass of the gas in cylinder A to the mass of the gas in cylinder B. Which will be greater?

• The mass of the gas in cylinder A is greater than the mass of the gas in cylinder B.

• The mass of the gas in cylinder B is greater than the mass of the gas in cylinder A.

• The masses of the gases in both cylinders are equal.