Physics 0625 · IGCSE · Kinetic particle model of matter
Kinetic particle model of matter — practice question
A large test-tube holds a liquid at room temperature. An electric heater is placed in the liquid and switched on. The heater transfers thermal energy to the liquid, so its temperature rises until the boiling point is reached. The liquid then begins to turn into gas.
(a)[3]
Describe, in terms of molecules and their motion, how a liquid is different from a gas.
(b)[2]
Describe what happens to the liquid’s molecules as its temperature starts to rise.
(c(i))[1]
Explain, in terms of molecules, why thermal energy must be supplied to change the liquid into a gas.
(c(ii))[3]
Calculate the specific latent heat of vapourisation for this liquid.
Worked solution & mark scheme
This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Molecules are packed closely together” …