Physics 5054 · O Level · Specific heat capacity

Specific heat capacity — practice question

A steel rod that is very hot is cooled by dropping it into cold water, as shown in Fig. 3.1. Fig. 3.1 depicts a steel rod being put into a container of water.
(a)[3]

The steel rod has a mass of 2.0 kg and begins at 500 ^{\circ}C. Once it is placed in the water, it cools to 50 ^{\circ}C. The specific heat capacity of steel is $460\,\text{J}\,(\text{kg }^{\circ}\text{C})^{-1}$. Calculate the thermal energy (heat) lost by the steel rod as it cools to 50 ^{\circ}C.

(b(i))[1]

State one difference between boiling and evaporation.

(b(ii))[2]

As the water cools, the rate of evaporation falls. Explain why this occurs, using ideas about molecules.

Worked solution & mark scheme

This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: Uses E = mc\Delta T

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