Problem: Use standard enthalpies of formation to calculate the standard change in enthalpy for the melting of ice. (The ΔH˚f for H2O(s) is –291.8 kJ/mol.) Use this value to calculate the mass of ice required to cool 360 mL of a beverage from room temperature (25.0˚C) to 0.0˚C. Assume that the specific heat capacity and density of the beverage are the same as those of water.

FREE Expert Solution

$\mathbf{-}{\mathbf{q}}_{\mathbf{water}}\mathbf{ }\mathbf{=}\mathbf{ }{\mathbf{q}}_{\mathbf{ice}}$

Step 1

$$\begin{gathered} {\mathbf{q}}_{\mathbf{water}}\mathbf{ }\mathbf{=}\mathbf{ }\mathbf{mc}\mathbf{∆}\mathbf{T} \\ {\mathbf{q}}_{\mathbf{water}}\mathbf{ }\mathbf{=}(360 \mathrm{mL}\times \frac{0.998 g}{1 \mathrm{mL}})(4.18 \frac{J}{g·°C})(0.0°C - 25.0°C) \end{gathered}$$

q_water = -37544.76 J