Question

A steam engine intakes 50g 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 × 10³ cal.

Answer 1

Answer is 31 

Heat rejected  = mL_f + mSΔT

 = (50 x 540) + 50 (1) (100 - 20)

 = 31000 Cal

 = 31 x 10³ Cal