Questions 1. Explain why the experiments can give only approximate values for the specific latent heat of fusion of water and the specific latent heat of vaporisation of water?

2. An electric kettle which is rated at 2250 W contains 0.8 kg of water. It takes 150 s to heat the water from 10°C to 100°C. The specific heat capacity of water is 4200 J kg−1 K−1.
a Calculate:
i the heat energy produced by the kettle in this time

ii the heat taken in by the water in this time.

b Suggest two reasons for the difference between these two quantities.