Pupil sheet · Gas pressure and temperature
Gas pressure and temperature — return questions
Name ______________________ Date ____________
Use one to two weeks after the lessons. Keep the notes and the lesson closed.
1. explain / state / calculate / describe
Keep the lesson closed. (a) Explain how a gas exerts a pressure on the walls of its container. (b) State what is meant by the pressure of a gas, in terms of force. (c) A fixed mass of gas is squeezed into a smaller volume at a constant temperature. Explain, in terms of particles, why its pressure rises. (d) 80 cm³ of air at 100 kPa is squeezed slowly, at a constant temperature, to 50 cm³. Calculate its new pressure. (e) Describe the shape of the graph of p against V, and of p against 1/V, for a fixed mass of gas at a constant temperature.
How a gas exerts a pressure
What pressure is
Why squeezing raises the pressure
The new pressure
The two graphs
2. explain / state / calculate
Keep the lesson closed. (a) A fixed mass of gas is heated at a constant volume. Explain, in terms of particles, why its pressure rises. (b) State the equation that links a temperature T in kelvin to the same temperature θ in °C. (c) Convert 100 °C into kelvin, and 250 K into °C. (d) For a gas at a constant volume, a graph of pressure against temperature in °C is a straight line. Carried on to colder temperatures, at what temperature would it reach zero pressure? What is this temperature in kelvin? (e) The temperature of a room rises from 15 °C to 25 °C. By how many kelvin does it rise?
Why the pressure rises
The equation
The two conversions
Where the line reaches zero, in °C and K
The rise in kelvin
3. describe / explain / state
Keep the lesson closed. (a) Describe what happens to a solid, a liquid and a gas when they are warmed (the gas free to expand, so its pressure stays the same) and when they cool again. (b) Put solids, liquids and gases in order, from the one that expands most to the one that expands least, and explain the order in terms of particles. (c) State two everyday uses of thermal expansion. (d) State two problems caused by thermal expansion, and how each one is avoided. (e) Describe what happens to a straight bimetallic strip of brass and steel when it is heated. Brass expands more than steel.
Warming and cooling
The order, explained
Two uses
Two problems and how they are avoided
The bimetallic strip