Question

The heat required (in $cal$) to change 10 g ice at $0^{o}C$ to steam at ${100}^{o}C$ is
( Heat of fusion and heat of vaporization for $H_{2}O$ are 80 cal/g and 540 cal/g respectively. Specific heat of water is 1 cal/g)

• A. 6500
• B. 7200

• C. 5400
• D. 6000

Answer 1

The correct option is B 7200

The heat required for the melting of ice is $10\times 80=800cal$

The heat required for evaporation of water is $10\times 540=5400$

The heat required for changing the temperature of water from $0^{0}C$ to ${100}^{0}C$ is $10\times 1\times 100=1000cal$

Total heat required for the entire process is $800+5400+1000=7200cal$

Hence, the correct option is $\text{B}$