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3.3.1 Gas Pressure

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  1. Gas pressure is the force per unit area exerted by the gas molecules as they collide with the surface of an object.
  2. In SPM, especially in paper 2 essay question, you need to know how the gas pressure is produced. (See question below)
Question:
Explain how gas pressure is produced in a closed container?

Answer:
  1. Gas molecules in a container are in constant and random motion.
  2. As a result, the gas molecules collide on the wall of the container.
  3. After colliding on the wall, the gas molecules bounce off, and the direction change creating a change of momentum to the molecule of the gas.
  4. The change of momentum produces a force on the wall.
  5. The force per unit area is the pressure on the wall.