When a solution of 1.691 g of silver nitrate is mixed with an excess of sodium chloride in a calorimeter of heat capacity 216 J.( $\circ$ C)^-1,the temperature rises 3.03 $\circ$ C.What is the reaction enthalpy?

Question

Quizplus · Accepted Answer

The reaction equation is: AgNO3 + NaCl -> AgCl + NaNO3
The limiting reagent is NaCl, meaning all of the AgNO3 will react. 
The amount of heat absorbed by the calorimeter can be calculated using q = mcΔT where m is the mass of the solution (assumed to be equal to the mass of water since density isn't given), c is the heat capacity of water (4.18 J/g°C), and ΔT is the change in temperature (3.03°C). 
q = (1.691 g AgNO3 / 169.87 g/mol) × (1 mol AgCl / 1 mol AgNO3) × (-216 J/g°C) × (-3.03°C) = -65.7 kJ/mol AgNO3
The negative sign indicates that the reaction is exothermic (releasing heat). Since the question asks for the reaction enthalpy, the answer is the opposite of the value calculated for q: +65.7 kJ/mol AgNO3.

When a Solution of 1 ∘\circ∘ C)-1,the Temperature Rises 3 ∘\circ∘ CWhat Is the Reaction Enthalpy? A)(-65

When a Solution of 1 $\circ$ C)^-1,the Temperature Rises 3 $\circ$ CWhat Is the Reaction Enthalpy?
A)(-65