A 13.0-g sample of ice at -13.0°C is mixed with 105.0 g of water at 78.0°C. Calculate the final temperature of the mixture assuming no heat loss to the surroundings. The heat capacities of H2O(s) and H2O(l) are 2.08 and 4.18 J/g · °C, respectively, and the enthalpy of fusion for ice is 6.02 kJ/mol.

1 answer

q to raise temperature of ice from -13C to zero C (but remain as ice).
q1 = mass ice x specific heat ice x (Tfinal-Tinitial)

q to melt ice at zero C and remain at zero C.
q2 = mass ice x heat fusion

q to raise melted ice from zero C to final T.
q3 = mass melted ice x specific heat water x (Tfinal-Tinitial)

q to lower temperature of hot water to final T.
q4 = mass hot water x specific heat x (Tfinal-Tinitial).
q1 + q2 + q3 + q4 = 0

Substitute each portion into q1 + q2 .... and solve for Tfinal.