Question

Steam at 100°C is passed into 20 g of water at 10°C. When water acquires a temperature of 80°C, the mass of water present will be [Take specific heat of water = 1 cal g^-1°C^-1 and latent heat of steam = 540 cal g^-1]

(a) 24 g

(c) 42.5 g

(b) 31.5 g

(d) 22.5 g

Answer 1

Correct option  (d) 22.5 g

Explanation:

Specific heat of water s_w = 1 cal g^-1°C^-1

Latent heat of steam,  Ls = 540 cal g^-1

Heat lost by m g of steam at 100°C to change into water at 80°C is