Question

A block of ice at $-{12}^{\circ }\text{C}$ is slowly heated and converted into steam at ${100}^{\circ }\text{C}$. Which of the following curves best represents this event?

• A.
• B.
• C.
• D.

Answer 1

The correct option is A


In a phase transition from ice to steam,
Initially, the ice at $(-{12}^{\circ }C)$ is slowly heated, thereby the temperature will start increasing till it reaches $0^{\circ }\text{C}$.
At $0^{\circ }\text{C}$, phase change occurs and ice will convert to water.
During the phase change, the temperature of the substance remains same and the heat is absorbed to assist the phase change, which is called as latent heat.
Again, when more heat is supplied, temperature starts to increase till further phase change happens between water and steam at ${100}^{\circ }\text{C}$ when latent heat is again absorbed to facilitate the phase change.
This transition is clearly represented by the graph in option (a).
Hence, option (a) is the correct answer.