Homework Help: Find q(system) in joules

1. Sep 1, 2013

JoeMann

1. The problem statement, all variables and given/known data

OCl–(aq) + Cl–(aq) + 2H+(aq) Cl2(aq) + H2O ΔrH = -202 kJ mol–1
25.0mL of a solution 0.400mol L–1 in both OCl– and Cl– was reacted with excess hydrochloric acid. The mass of the solution after mixing was 100 g.
n(reaction) = 0.0100 mol

Find q(system) in joules.
Assume that the temperature change of the vessel in which the experiment is carried out is negligible
Assume that the heat capacity of the mixture is the same as the specific heat capacity of water (4.184 J g–1 K–1).

2. Relevant equations

I know somewhere you have to use the formula q = mcΔT but im unsure what to do because there is no temperature in the question.
3. The attempt at a solution

I have tried multiplying the mass and temp change but I think i am wrong. Please help?

2. Sep 1, 2013

Staff: Mentor

It is not about q = mcΔT.

You are told how much heat is produced per mole of produced Cl2. How many moles were produced?