Question

Explain the following temperature Vs. time graph:

Answer 1

At point A, water is in solid state i.e. ice.
Between A to B ice is changing to water without rise in temperature {Melting of ice} so 00C is the melting point. From B to C temperature rises with time as heat is provided to water. At point C to D, water is changing to steam without change in temperature. So it is the boiling point. Hence 1000C is the boiling point of water.