(3) Particle Model and Pressure Flashcards
Describe the motion of gas molecules
They move in a constant random motion
What effect does increasing the temperature have on the pressure of a gas?
When held at a constant volume, the pressure of the gas will increase as the temperature increases
What factor affects the average kinetic energy of gas molecules?
- The temperature of the substance
(The higher the temperature, the higher the average kinetic energy of the molecules)
Why does pressure increase as temperature increases?
- kinetic energy of molecules increases
- collisions between molecules become more frequent
- greater force and therefore pressure
Are there more collisions in a low pressure gas or a high pressure gas?
In a high pressure gas there are more collisions per second
Explain how increasing the volume of a gas results in a decrease of pressure
- molecules become more spread out
- the rate of momentum decreases and so force exerted on the container decreases, resulting in a lower pressure
What is the unit for pressure?
Pascals (Pa)
Equation for pressure
Pressure = force/ area
Pressure= Pascals Area= m² Force= Newtons
Equation for a fixed mass of gas held at a constant temperature
Pressure x volume = constant
(PxV=constant)
Pressure= Pascals Volume= m³
What is work?
Work is the transfer of energy by a force
What increases when you do work on a gas?
The internal energy of the gas (this can lead to an increase in temperature)
Why does the temperature of air inside a bike pump increase when it is pumped?
- work is done on a gas when it is compressed
- doing work on a gas increases it’s internal energy, so also increasing the kinetic energy of the molecules
- temperature increases with an increase of kinetic energy
