Question

The amount of heat needed to melt 2 kg of ice at its melting point, when latent heat of ice is 80 cal/g, is (1 cal = 4.184 J) options..
...40 x 10⁵J
... 6.7 x 10⁵ J
...3.35 x 10⁵J
... 1.675 X 10⁵J​

Answer 1

Answer:

Latent heat of ice is defined as the amount of heat needed to convert 1g of ice into water. As given in the question, its value is 80 cal/g.

Since 1 cal=4.184 J

80 cal/g=80×4.184 J/g

=334.72 J/g

Heat needed to melt 2 kg of ice is:

Heat = mass × latent heat of ice

=2×334.72 kJ

=669.44 kJ

answer is b