Q1+2. The diagram shows gas molecules trapped in a container. The molecules (particles) are moving very fast. they collide with the walls of the container producing a pressure.

1. Which of these statements best describes the effect of this pressure on the container?

• A. The pressure produces a force parallel to the surface of the container.
• B. The pressure produces a force at right angles to the surface of the container.
• C. The pressure produces energy parallel to the surface of the container.
• D. The pressure produces energy at right angles to the surface of the container.

2. If the container volume is increased, without changing the temperature of the gas, what happens to pressure of the gas?

• A. The pressure increases because the particles move and collide faster.
• B. The pressure increases because the particles hit the sides of the container more frequently.
• C. The pressure decreases because the particles move and collide more slowly.
• D. The pressure decreases because the particles hit the sides of the container less frequently.

3-6. A simple experiment is carried out using a gas syringe:

A pressure sensor is attatched to the end of the syringe, and the pressure reading taken as the gas volume is reduced. The reading is taken after a while to allow the temperature to remain constant. The results are shown in the green table below.

The formula linking pressure and volume is:   

p V = constant

Database Center for Life Science (DBCLS)

3. What are the likely missing volume units labelled X in the results table below?

• A) cm²
• B) cm³
• C) m²
• D) m³

4-6. What are the missing values in the results table for the syringe shown here?

7. Which of these statements best describes what happens to a gas trapped inside a bicycle pump when it is pushed inwards rapidly, reducing the volume of the gas?

• A. The temperature decreases due to work being done on the gas.
• B. The temperature increases due to work being done on the gas.
• C. The temperature decreases due to a force being applied on the gas.
• D. The temperature increases due to a force being applied on the gas.