Question

The problem statement, all variables and given/known data
When 5.00 g of NaOH(s) are added to 100 g of water using a calorimeter (with Cp = 493.24 J/K), the temperature rises from 25.0 to 37.5 °C. Calculate the molar heat of solution.
NaOH(s)--->Na(aq)+OH(aq)
Assume that the specific heat capacity of water is 4.18 J/gK and that of the NaOH(aq) solution is the same.

Answer 1

q = [mass H2O x specific heat H2O x (Tfinal-Tinitial)] + [Ccal x (Tfinal-Tinitial)]
Substitute and solve for q = delta H solution.
q/5.00 = delta H/gram.
delta H/g x (molar mass NaOH) = delta H in J/mol. Convert to kJ/mol.