When 500 mL of 0.100 MAgNO3 is combined with 500 mL of HCl in a coffee-cup calorimeter, the temperature changes from 23.40 ∘C to 24.21 ∘C. Calculate ΔHrxn for the reaction as written. Use 1.00 g/mL as the density of the solution and C=4.18J/(g⋅∘C) as the specific heat capacity.

Respuesta :

The heat released by the reaction is absorbed by the solution, resulting in the temperature change.

Mass of solution = density x volume
Mass = 500 x 1 = 500 grams

Heat absorbed:
Q = mCpΔT
Q = 500 x 4.186 x (24.21 - 23.4)
Q = 1,695 J

Moles of silver nitrate = molarity x volume in L
Moles of silver nitrate = 0.1 x 0.5
Moles of silver nitrate = 0.05

Heat of reaction = 1,695 / 0.05
Heat of reaction = 33.9 kJ/mol