Question

A generic solid, X, has a molar mass of 77.7 g/mol. In a constant-pressure calorimeter, 31.2 g of X is dissolved in 289 g of water at 23.00 °C.
The temperature of the resulting solution rises to 24.40 °C. Assume the solution has the same specific heat as water, 4.184 J/(g·°C), and that there\'s negligible heat loss to the surroundings. How much heat was absorbed by the solution?
How much heat was absorbed by the solution?

Answer 1

q = mass H2O X specific heat H2O x (Tfinal-Tinitial)

All the rest of that info is not needed UNLESS you want delta H/g and/or delta H/mol.
dH/g = q/31.2
dH/mol = q/g x (77.7 g/mol) = ?