When 1.375g CaO is added to 50 mL water at 25.0 degree C, the temperature of the water increases to 34.6 degree C. Given the specific heat is 4.184 j/g*degree C, how much heat is absorbed by the calorimeter?

Answer 1

q = mass H2O x specific heat H2O x (Tfinal-Tinitial) is the heat absorbed.
Then q/1.375 is heat absorbed per gram CaO and that x molar mass CaO is heat absorbed per mol CaO. I think those questions would follow although you didn't post them yet.