Question

4 kg of ice at `-15^(@)C` are added to 5 kg of water at `15^(@)C` . The temperature of the mixture equals
A. `-15^(@)C`
B. `0^(@)C`
C. ` 5^(@)C`
D. `15^(@)C`

Answer 1

Correct Answer - B
Heat released when 5 kg of water at `15^@)`C converts into `0^(@)`C water is , Q = mc`Deltatheta` = (5000)(1)(15) = 7500 cal. This heat can melt mass of water m = Q/L = `(75000)/(80)` = 937.5 g or 0.9375 kg. Since, whole of iceis not melting, temperature of mixture will be `0^(@)`C.