Question

The heating curve for ice initially at a particular pressure is given.

Choose the correct heating curve for the ice initially at $0{}^{\circ }\text{C}$, if the pressure is decreased.

• A.
• B.
• C.
• D.

Answer 1

The correct option is C

When we decrease the pressure, the melting point of ice increases. So, it will melt at a temperature greater than $0{}^{\circ }\text{C}$.
During the stage A to B, the temperature of ice increases and hence, it melts into water. The temperature remains constant during the melting of ice, even though heat is supplied continuously, because, the heat is used for changing the state of matter and not for increasing the temperature. So, the correct curve of the ice would look like this: