Acommon laboratory reaction is the neutralization of an acid with a base. when 50.0 ml of 0.500 m hcl at 25.0°c is added to 50.0 ml of 0.500 m naoh at 25.0°c in a coffee cup calorimeter, the temperature of the mixture rises to 28.2°c. what is the heat produced by the reaction.
a) 670 j
b) 1300 j
c) 27 kj
d) 54 kj
e) > 100 kj

B

Explanation:

In this calorimetry problem, the heat released by the reaction is equal to the heat absorbed by the solution (assumed to have the same specific heat capacity as water, 4.19 Jg⁻¹°C⁻¹).

The formula Q = mcΔt will be used to calculate the heat energy, where m is the mass, c is the specific heat capacity, and Δt is the change in temperature from final to initial.

The volume of solution is (50.0 + 50.0)mL = 100.0mL = 100.0g, since water has a density of 1.00g/mL.

The heat absorbed by the solution is then calculated.

Q = mcΔt = (100.0 g)(4.19 Jg⁻¹°C⁻¹)(28.2°C - 25.0°C) = 1340 J

The closest answer is B) 1300 J. This answer is obtained by including only two significant figures in the answer.