Pearson Edexcel International GCSE (9–1) · PHYSICS · Unit
Solids, Liquids and Gases
279 practice questions
Topics covered
Practice questions
121–130 of 133 · Easy
Question 121
1 mark · Easy
Answer and check →The temperature inside a refrigerator is 275 K. What is this temperature in degrees Celsius?
Question 122
2 marks · Easy
Answer and see the solution →Explain why scientists use the Kelvin scale, rather than the Celsius scale, when working with gas laws.
Question 123
1 mark · Easy
Answer and see the solution →A block of ice is stored at absolute zero. Describe the energy of its particles at this temperature.
Question 124
1 mark · Easy
Answer and check →The melting point of iron is 1535 °C. What is this temperature in Kelvin?
Question 125
5 marks · Easy
Answer and see the solution →A scientist traps a fixed mass of gas in a syringe sealed with a cap. She gently heats the syringe by placing it in warm water while making sure the plunger does not move. The initial temperature of the gas is 25°C and its pressure is 105 kPa. After heating, the gas temperature reaches 45°C. Assume the volume of the gas does not change.
(a)[1 mark]State which gas law links the pressure and temperature of a fixed volume of gas.
(b)[3 marks]Calculate the new pressure of the gas when it has reached 45°C. Give your answer to two significant figures.
(c)[1 mark]Explain, in terms of the motion of particles, why the pressure increases when the gas is heated.
Question 126
4 marks · Easy
Answer and see the solution →A fixed mass of gas is kept at a constant temperature of 300 K. The initial volume of the gas is 2.0 dm³ at a pressure of 100 kPa. The gas is then compressed to a pressure of 250 kPa.
(a)[1 mark]Name the law that relates the pressure and volume of the gas in this situation.
(b)[2 marks]Calculate the new volume of the gas after compression. Give your answer to two significant figures.
(c)[1 mark]State the assumption made about the temperature in order for this law to apply.
Question 127
4 marks · Easy
Answer and see the solution →A gas cylinder contains a fixed mass of oxygen at a pressure of 300 kPa and a temperature of 27°C. The gas escapes until the pressure drops to 100 kPa. The temperature does not change throughout the process.
(a)[2 marks]Explain, in terms of the number of particles, why the pressure in the cylinder decreases when gas escapes.
(b)[2 marks]If the initial volume of the gas was 4.5 litres, calculate the final volume of the remaining gas in the cylinder, assuming all other conditions stay the same.
Question 128
4 marks · Easy
Answer and see the solution →A rectangular metal bar has a length of 10 cm, a width of 2 cm and a height of 5 cm. Its mass is 1.0 kg.
(a)[1 mark]Calculate the volume of the metal bar. Give your answer in cm³.
(b)[3 marks]Calculate the density of the metal. Give your answer in kg/m³.
Question 129
4 marks · Easy
Answer and see the solution →A block with a weight of 30 N stands on a platform of area 0.015 m².
(a)[1 mark]State the formula for pressure under a solid, using symbols.
(b)[3 marks]Calculate the pressure the block exerts on the platform. Give the unit.
Question 130
4 marks · Easy
Answer and see the solution →An aquarium is filled to a depth of 0.5 m with water of density 1000 kg/m³. The gravitational field strength is 10 N/kg.
(a)[1 mark]State the equation for the pressure difference due to a liquid column, using symbols.
(b)[3 marks]Calculate the pressure at the bottom of the aquarium due to the water.