Specific latent heat: Practice Questions

The graph shows how the temperature of a solid substance changes as it is heated at a constant rate. Which segment of the graph corresponds to the energy absorbed as the specific latent heat of fusion?

The cooling curve for a pure substance is shown in the diagram. The substance has a mass of \(0.40\text{ kg}\) and the rate of thermal energy loss to the surroundings is constant at \(20\text{ W}\). What is the specific latent heat of fusion of the substance?

How much total thermal energy is needed to change \(200\text{ g}\) of ice at \(0\text{ }^{\circ}\text{C}\) to water at \(20\text{ }^{\circ}\text{C}\)?
(Specific latent heat of fusion of ice = \(3.34 \times 10^5\text{ J/kg}\); Specific heat capacity of water = \(4200\text{ J/(kg K)}\))

In an experiment to measure the specific latent heat of fusion of ice, two funnels containing crushed ice are used. Funnel A contains a heater that is switched on, while Funnel B contains no heater. What is the purpose of using Funnel B?

A \(500\text{ W}\) heater is used to boil water. Once the water reaches \(100\text{ }^{\circ}\text{C}\), it is observed that \(0.10\text{ kg}\) of water turns into steam in \(440\text{ s}\). What is the specific latent heat of vaporization of water based on these results?

An electric heater of power \(P\) is used to boil away a mass \(m\) of a liquid at its boiling point in a time interval \(t\). Derive an expression for the specific latent heat of vaporisation, \(L_v\), of the liquid in terms of \(P\), \(m\), and \(t\).