How much heat is produced when 100 mL of 0.250 M HCl (density, 1.00 g/mL) and 200 mL of 0.150 M NaOH (density, 1.00 g/mL) are mixed?

HCl(aq) + NaOH (aq)

NaCl(aq) + H

_{2}O(l) ΔT = -58 kJ

If both solutions are at the same temperature and the heat capacity of the products is 4.19 J/g°C, how much will the temperature increase? What assumption did you make in your calculation?

My answer:

Reaction given produces 58 kJ of heat with 1 mol of NaOH. We have 0.150 M of NaOH (limiting reagent) so it will produce 0.150 M × -58 kJ/1.0 M= -8.7 kJ of heat.

We know that q=cm∆T, substituting the values we have , in the equation -8.7 kJ = 4.19 J/g℃ × 300 g × ∆T, ⇒ ∆T= 6.9°C.

Is this answer correct?