Question

1 g of steam at 100°C can melt how much ice at 0°C? Latent heat of ice = 80 cal/g and latent heat of steam = 540 cal/g.

(1) 4 grams 

(2) 6 grams

(3) 8 grams 

(4) 10 grams

Answer 1

Correct Answer is: (3) 8 grams

Heat required by ice for melting of m g of ice = mL = m × 80 cal

Heat available with steam for being condensed and then brought to 0°C

= 1 × 540 × 100

= 640 cal

m × 80 = 640

or m = 640/80 = 8 grams