## Specific Latent Heat Practice Questions

1. Fill the blanks in the following sentences :

(a) A solid must be given .......................... heat of ................................ before it can be melted into a liquid.

(b) A liquid must be given ........................ heat of ........................................ before it can be boiled into a gas.

(c) The energy needed to melt a solid is used to break the ........................ between the molecules so that they can move ........................... freely.

(d) The specific latent heat of fusion is the amount of energy (measured in ...........................) needed to melt ....... kg of a solid into a ............................ without changing its ..............................................

2. Explain why a scald from steam at 100 degrees C is very much worse than a scald from water at 100 degrees C.

3. Why is ice at 0 degrees C better at cooling drinks than the same amount of water at 0 degrees C?

4. An electric kettle produces 2000 J of energy each second. It is filled with water, weighed and switched on. After

coming to the boil, it is left on for a further 120 seconds and is then switched off. It is found to be 90 g lighter.

Calculate the specific latent heat of fusion from this data

(a) A solid must be given .......................... heat of ................................ before it can be melted into a liquid.

(b) A liquid must be given ........................ heat of ........................................ before it can be boiled into a gas.

(c) The energy needed to melt a solid is used to break the ........................ between the molecules so that they can move ........................... freely.

(d) The specific latent heat of fusion is the amount of energy (measured in ...........................) needed to melt ....... kg of a solid into a ............................ without changing its ..............................................

2. Explain why a scald from steam at 100 degrees C is very much worse than a scald from water at 100 degrees C.

3. Why is ice at 0 degrees C better at cooling drinks than the same amount of water at 0 degrees C?

4. An electric kettle produces 2000 J of energy each second. It is filled with water, weighed and switched on. After

coming to the boil, it is left on for a further 120 seconds and is then switched off. It is found to be 90 g lighter.

Calculate the specific latent heat of fusion from this data