A spirit lamp supplying heat at a rate of 50 W is used to melt 0.025 kg of ice at 0 °C taken in a container. If all the ice in the container is melted in 168 s…

Given,

• Power of spirit lamp (P) = 50 W
• Mass of ice (m) = 0.025 kg
• Fixed temperature (T_i) = 0 °C
• Time Taken (t) = 168 s

Let specific latent heat of ice be L_i.

Now,

Heat gained by ice (Q) = P x t = 50 x 168 = 8400 J

Also,

L_i = $\frac {\text Q}{\text m} = \frac {8400}{0.025}= \frac{8400000}{25}$ = 336 x 10³ J kg^-1

Hence, specific latent heat of fusion of ice is 336 x 10³ J kg^-1.