A beaker contains 0.25kg of water at room temperature.
The beaker of water is heated until the water reaches boiling point (100°C).
The specific heat capacity of water is 4200 J/kg°C.
The total amount of thermal energy supplied to the water is 84 000J.
(i)
Calculate the temperature of the water before it was heated. Use an equation selected from the list of equations at the end of this paper.
[3]
temperature before heating = ............................................... °C
(ii)
The heating continues until 0.15 kg of the water has turned into steam. The thermal energy needed to turn the boiling water into steam is 0.34 MJ.
Calculate the specific latent heat of vapourisation of water.
Use an equation selected from the list of equations at the end of this paper.
[2]
specific latent heat = ................................... MJ/kg
(iii)
The graph in Figure 13 shows how the volume of 1kg of water changes with temperature.
Describe how the density of water changes with temperature over the range of temperature shown in Figure 13.
Calculations are not required.