An experiment takes `10` minutes to raise the temperature of water in a container from `0^(@)C "to" 100^(@)C` and another `55` minutes to convert it totally into steam by a heater supplying heat at a uniform rate. Neglecting the specific heat of the container and taking specific heat of water to be `1 "cal//g ^(@)C`, the heat of vapourization according to this experiment will come out to be:-

Options

A. `540"cal"//g`
B. `530"cal"//g`
C. `560"cal"//g`
D. `550"cal"//g`

Answer

D

Explanation

Let M is mass of water and P is amount of heat supplied per unit minute.
`MS_(W)(100-0) = P xx 10 …..(i)`
`ML_(V) = P xx 55 …. (ii)`
(i)/(ii) we get `L_(V) = 550"cal"//"g"`