gas stimulation

Question

1. What two factors does the speed of a molecule depend on?
2. What is the equation that defines pressure?
3. What is creating the force on the sides of the container?
4. On a molecular level, explain two reasons why temperature and pressure are related in this way?
5. On a molecular level, why are the pressure and number of molecules related in this way?
6. On a molecular level, why are pressure and volume related in this way?

Answer 1

The speed of a molecule depends on the temperature as well as the molar mass (or just mass) of that molecule. Pressure can be defined as either

Pressure = Force/Area or P = F/A

OR

(P)Pressure * V(Volume) = n(moles)R(constant)T(Temperature) or PV=nRT

The force on the sides of the container is created by the particles’ fast, random motion and collisions with the inside of the container. The wall must provide a force to prevent the particle from breaking through and also change the direction of the particle toward the inside the container.

The greater the temperature, the greater the pressure. As the temperature increases, the average KE of the particles increases, which means their speed is increasing inside the container. When they collide with the walls at higher speed, they create a larger force and cause an increase in pressure. This also means if you place more mass in the container by either using larger particles or adding more particles, these particles have less space to move and will bump into each other - and the walls - more often. This increases the pressure and therefore the temperature must increase as well.