What are freezing and freezing point ?

A child running a temperature of $101\,^{\circ} F$ is given an antipyrin (i.e. a medicine that lowers fever) which causes an increase in the rate of evaporation of sweat from his body. If the fever is brought down to $98\,^{\circ} F$ in $20$ minutes, what is the average rate of extra evaporation caused, by the drug (in $g/min$). Assume the evaporation mechanism to be the only way by which heat is lost. The mass of the child is $30\; kg$. The spectfic heat of human body is approximately the same as that of water, and latent heat of evaporation of water at that temperature is about $580\; cal \;g^{-1}$.

Latent heat of $1\,gm $ of steam is $536 \,cal/gm,$ then its value in $joule/kg$ is

A substance is cooled at a constant power. Its temperature vs time graph is shown. The value of $S_{solid} : S_{liquid} : S_{gas}$

The figure given below shows the cooling curve of pure wax material after heating. It cools from $A$ to $B$ and solidifies along $BD$. If $L$ and $C$ are respective values of latent heat and the specific heat of the liquid wax, the ratio $L/C$ is