Question

For a $5gm$ substance the heat supplied (in $cal$) and temperature (in ${}^{o}C$) curve is given below. Then the specific heat of substance for liquid state will be :

• A. $1cal/g{m}^{o}C$
• B. $0.2cal/g{m}^{o}C$
• C. $2.5cal/g{m}^{o}C$
• D. can't be obtained

Answer 1

The correct option is B $0.2cal/g{m}^{o}C$

If we study the graph , we see that heat supplied to the substance , in liquid state to change the temperature from $0^{o}C$ to ${100}^{o}C$ is ,

$Q=220-120=100cal$ ,

given $m=5g$ ,

by , $Q=mc\Delta T$ ,

$100=5\times c\times (100-0)$ ,

or $c=1/5=0.2cal/g^{o}C$