A steam engine intakes 50   g of steam at 100 ° C per minute and cools it down to 20 ° C . If latent heat of vaporization of steam is 540   cal   g - 1 , then the heat rejected by the steam engine per minute is _____ × 10 3   cal (Given : specific heat capacity of water : 1   cal   g - 1 C ∘ - 1 )

Step-by-step solution

Heat rejected by the steam engine per minute will be equal to latent heat per minute plus heat rejected by the water to cool down. ∆ H ∆ t = ∆ m ∆ t L + ∆ m ∆ t s ∆ T ⇒ ∆ H ∆ t = 50 × 540 + 50 × 1 × 80 = 31000   cal   min - 1 = 31 × 10 3   cal   min - 1