pressure

• explain the pressure of a gas in terms of the motion of particles 


  the particles move in random directions , when they collide with the walls of a container they exert a force which acts at a right angle to the container , this causes pressure
• state the equation used to calculate pressure

  pressure = force / area newton , mpressure = force / area newton , meters squared
• what factor affects the average kinetic energy of gas molecules

  the temperature of the gas , the higher the temperature , the higher the average kinetic energy of the molecules
• what effect does increasing temperature have on the pressure of a gas when held at constant volume


  gas pressure will increase as temperature increases
• why does pressure increase as temperature increases

  kinetic energy of the molecules increases , collsisons between the molecules becomes more frequent , greater rate of change of momentum , greater force and therefore pressure
• if gas a is at a low pressure , and gas b at a high pressure , what can be said about the rate of collisions in each gas


  there are more collisions per second in gas b than in a , the rate of collisions in b is higher

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• describe the force that the pressure of a gas exerts on the walls of its containers

  the net force acts at right angles to each surface of the container , the force increases as pressure increases
• explain how increasing the volume of a gas results in a decrease of pressure

  molecules become more spread out so rate of collision decreases , rate of change of momentum decreases , and so force exerted on container decreases , resulting in a lower pressure
• what can be said about the product of pressure and volume for a fixed mass of gas at a constant temperature


  it is constant
• what is the unit used for pressure

  pascal
• what increases when you do work on a gas

  the internal energy of the gas , this can also lead to an increase in temperature
• what is absolute 0

  -273 degrees , particles have no kinetic energy and cannot move
• what equation can be used to calculate the pressure/volume for a gas for which the mass is fixed and the temperature is constant 


  pressure(1) x volume(1) = pressure(2) x volume(2)
• 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 its internal energy , so it increases the average kinetic energy of the molecules , temperature increases with a greater average kinetic energy