Question

1. Calculate what mass of water can be changed to steam if 10.6kJ of heat energy is supplied to the water at 100⁰C. (Specific latent heat of vaporization of water = 2.26x10⁶J/kg)

1. Ammonia is vaporised in order to freeze an ice rink.

a)  Find out how much heat it would take to vaporise 1 g of ammonia.

    (Specific latent heat of vaporisation of ammonia = 1.34 x 10⁶ J/kg      Specific latent heat of fusion of ice = 3.34 x 10⁵ J/kg).

Answer 1

1)

$Q=Lm,\implies m=\frac QL,$

$m=\frac{10.6\cdot 10^3}{2.26\cdot 10^6}=4.7~g,$

2)

$Q=Lm,$

$Q=1.34\cdot 10^6\cdot 1\cdot 10^{-3}=1.34~kJ$