The average molar heat capacities of ice and water are `37.6 mol^(-1)` and `75.2 J mol^(-1)` respectively and the enthalpy of fusion of ice is 6.020 kJ `mol^(-1)`. The amount of heat required to change 10 g of ice at `-10^(@)C` to water at `10^(@)C` would be

Options

A. 2376 J
B. 4752 J
C. 3970 J
D. 1128 J

Answer

C

Explanation

The entire process of changing of 10g. of ice at `-10^(@)C` to water at `+10^(@)C` can be divided into
Ice `(-10^(@)C) overset(Delta H_(1))rarr "Ice " (0^(@)C) overset(Delta H_(2))rarr "water " (0^(@)C) overset(Delta H_(3))rarr " water"(10^(@)C)`
`Delta H_(2) = (10)/(18) xx 6.012 xx 10^(3)J = 2240J`
`Delta H_(3)= (10)/(18) xx 75.6 xx 10= 420J`
Total heat required `=210 + 3340 + 420 = 3970J`