Question

Calculate the total amount of heat energy required to convert $100g$ of ice at $-{10}^{\circ }C$ completely into water at ${100}^{\circ }C$. Specific heat capacity of ice = $2.1J{g}^{-1}{K}^{-1}$, specific heat capacity of water = $4.2J{g}^{-1}{K}^{-1}$, specific latent heat of ice = $336J{g}^{-1}$

• A. $77.7\times {10}^{4}J$
• B. $7.77\times {10}^{-4}J$
• C. $777\times {10}^{4}J$
• D. $7.77\times {10}^{4}J$

Answer 1

The correct option is D $7.77\times {10}^{4}J$

Heat required = heat required to bring to ${10}^{o}C$ +latent heat for conversion of ice to water+heat require to raise the water temperature by ${100}^{o}C$

$Q=mc\Delta T$ for temperature change in same phase

$Q=mL$ for phase change at same temperature.

$Q=100\times 2.1\times 10+100\times 336+100\times 4.2\times 100$

$Q=7.77\times {10}^{4}J$