Question

What mass of steam initially at l30°C is needed to warm 200 g of water in a 100 g glass container from 20.0°C to 50.0°C. Take specific heat capacity of steam to be 2.01 x l0^3 J/ kg.°C and that of water to be 4.19 x 10^3 J/ kg.°C.

Hint: The steam loses energy in three stages. In the first stage, the steam is cooled to 100°C where ms is the mass of the steam. In the second stage, the steam is converted to water without the change in temperature. In the third stage, the water created from steam is reduced to water at 50°C.