Question

Latent heat of vaporisation of water is $22.6 \times 10^{5} \,J / kg$. The amount of heat needed to convert $100 \,kg$ of water into vapor at $100{ }^{\circ} C$ is

• A. $11.3 \times 10^{5} \, J$
• B. $11.3 \times 10^{6} \, J$
• C. $22.6 \times 10^{6} \,J$
• D. $22.6 \times 10^{7} \,J$

Answer 1

Answer: (D)

Heat required to convert water at $100^{\circ} C$ into steam at $100^{\circ} C$ is $Q=m L$
where, $m=$ mass $=100 \,kg$ and
$L=$ latent heat $=226 \times 10^{5} J / kg$
$\therefore Q=100 \times 22.6 \times 10^{5}=22.6 \times 10^{7}\, J$