Chapter 5 Principles of Chemical Reactivity: Energy and Chemical Reactions - Study Questions - Page 217b: 42

$-95.55\ kJ/mol$

From the definition of heat capacity: $140.2\ g\times 4.2\ J/g.K \times(28.8-20.2)\ K)=5064.0\ J$ Negative value because it's an exothermic process. Number of moles of $H_2SO_4$: $5.2\ g\div 98.07\ g/mol=0.053\ mol$ Enthalpy of dissolution: $-5.064\ kJ/0.053\ mol=-95.55\ kJ/mol$