Question

 Calculate the amount of heat given out while converting 100 g of water at 50°C into ice at -5°C. (refer Q.9 for data).

Answer 1

Amount of heat given out while converting water from 50°C to 0°C

= m x c x θ

= 100 x 4.2 x 50 

= 21000 J

Amount of heat given out while converting water at 0°C to ice at 0°C = mL

= 100 x 330

= 33000 J

Amount of heat given out while converting ice from 0°C to 50°C

= 100 x 2.1 x 5

= 10500 J

Total heat required during the process = 64500 J