A sample of 2.50 g LiI is added to 75.0 mL of water initially at 21.0°C. After stirring and dissolving, the temperature of the solution is 24.3°C. Assume that the specific heat of the solution is 4.184 J/g°C, the density is 1.00 g/mL, and the calorimeter constant is 40.0 J/°C. Determine the heat of solution for LiI (ΔHsoln).

I don't know how to do this.
I know that is is
Qrxn = Qsolution + Qcal
then i am suppose to covert J to KJ
then deltaHxrn = Qrxn/moles solute

So q of solution is

q = mass H2O x specific heat H2O x delta T.
qcal = (40J/C)*delta T.
You go from there.