When 1.00 L of 1.00 M Ba(NO₃)₂ at 25.0°C is mixed with 1.00 L of 1.00 M Na₂SO₄ at 25°C in a calorimeter, the white solid BaSO₄ forms, and the temperature of the mixture increases to 28.1°C. Assuming that the calorimeter absorbs only a negligible quantity of heat, that the specific heat capacity of the solution is 4.18 J°C^–1 g^–1, and that the density of the final solution is 1.0 g/mL, calculate the enthalpy change per mole of BaSO₄ formed.