A coffee-cup calorimeter is used to measure the heat exchanged when the following reaction is performed :

Pb(NO3)2 + 2 NaI(aq) → PbI2(s) + 2 NaNO3(aq)

Specifically…A 6.00-gram sample of sodium iodide is added to 200 mL of a 0.22 M lead(II) nitrate solution. Before the solid is added, the solution has a temperature of 22.6˚C. The temperature is recorded to be 24.2˚C when the reaction is complete.

Use this information to determine the ΔHrxn. Assume that the specific heat and density of the mixture are the same as that for pure water.