Question

200 g of ice at 0degree Celcius converts into water at 0degree Cecius in 1 minute when heat is supplied to it at a constant rate. In how much time 200g of water at 0degree Celcius will change to 20degree Celcius? Take specific latent heat of ice=336 J g-1.

Answer 1

Dear Student

Mass of ice m=200g = 0.2 Kg
Ice converted into water
Q=mL=200 x 336= 67200 J
Rate of heat transfer R=Q/t
here t=1 minute=60 second

R=67200/60 = 1120 J/s

Specific heat of water = 4.2 J/g C⁰
Q=msT= 200 x 4.2 x 20= 16800 J

Then time to raise the temperature 20 C⁰

t=Q/R =16800/1120= 15 Second

t=15 second

Regards