Question

How much heat would be required to convert $14$ kg of ice at $0^o$ C into water of $0^o$ C ?

• A. 4704 J
• B. 4704 kJ
• C. 336 J
• D. 336 kJ

Answer 1

The correct option is B 4704 kJ

We know that , to change the state of a matter, heat is required . Heat required to change a solid into liquid is given by ,

$Q=mL$ ,

where $L=$ latent heat of fusion ,

now given that , $m=14kg=14\times {10}^{3}g$ , and latent heat of fusion of ice is , $L=80cal.g^{-1}$ ,

hence , $Q=(14\times {10}^3\times 80)cal$ ,

by , $W=QJ=14\times {10}^3\times 80\times 4.2=4704\times {10}^3=4704kJ$