Chapter 5, Problem 5.64QE

Dissolving 6.00 g CaCl₂ in 300 mL of water causes the temperature of the solution to increase by 3.43 °C. Assume that the specific heat of the solution is 4.18 J/g · K and its mass is 306 g.

1. (a) Calculate the enthalpy change when the CaCl₂ dissolves. Is the process exothermic or endothermic?
2. (b) Determine ΔH on a molar basis for

${\text{CaCl}}_{\text{2}}\left(\text{s}\right)\stackrel{{\text{H}}_{\text{2}}\text{O}}{\to }{\text{Ca}}^{2+}\left(\text{aq}\right)+2{\text{Cl}}^{-}\left(\text{aq}\right)$