Question

Two 20.0-g ice cubes at –11.0 °C are placed into 265 g of water at 25.0 °C. Assuming no energy is transferred to or from the surroundings, calculate the final temperature of the water after all the ice melts.

Heat Capacity of H₂O(s) 37.7 J/(mol x K)

Heat Capacity of H₂O(l) 75.3 J/(mol x K)

Enthalpy of Fusion of H₂O 6.01 kJ/mol

Answer in Degrees Celsius

Answer 1

The initial temperature of water= 25 ⁰C

Final temperature after equilibrium= to be determined = x

The initial temperature of ice cubes= -11 ⁰C

Now, assuming no energy is transferred to or from the surroundings, heat gained by ice cubes at -11 ⁰C = heat lost by water at 25 ⁰C.

i.e., m*Cp*deltaT (ice cubes)+ enthalpy of fusion of water = m*Cp*deltaT (water)

{20g* 37.7 J/mol K* (x-(-11)) K }+ 6.01 kJ/mol = {265g* 75.3 J/mol K* (25-x) K }

Solving the above equation, x= 23.39 ⁰C