A 6.3 g sample of solid NH4NO3 is dissolved in 50g water, causing the temperature to
drop from 24 degrees Celsius to 19 degrees Celsius. Calculate the AH solution in J/mol.
q = dH = mass x specific heat H2O x delta T
q = 50 g x 4.184 J/g*C x 5 = 1046 J
That's 1046 J for 6.3 g NH4NO3. Convert that to J/mol
Post your work if you get stuck.