When Pure Sodium Hydroxide Is Dissolved in Water, Heat Is

When pure sodium hydroxide is dissolved in water, heat is evolved. In a laboratory experiment to measure the molar heat of solution of sodium hydroxide, the following procedure was followed. To a calorimeter containing 3.00 × 10² g of water at 20.00 °C, 10.65 g of NaOH, also at 20.00 °C was added. The temperature of the solution, which was monitored by a digital thermometer with negligible heat capacity, increased to 28.50 °C. If the specific heat of the mixture is 4.184 J g^-1 °C^-1, and the small heat capacity of the calorimeter is ignored, what is the heat evolved, per mole of sodium hydroxide?Hint: Do not ignore the specific heat of water given in this problem and be sure to convert NaOH to moles before proceeding.

A) -37.4 kJ
B) -41.5 kJ
C) -45.5 kJ
D) -90.5 kJ
E) -153 kJ