10.1 g CaO is dropped into a styrofoam coffee cup containing 157 g H2O at 18.0 degrees C. If the following reaction occurs, then what temp will the water reach, assuming the cup is a perfect insulator and the cup absorbs only a negligible amount of heat?
CaO(s) + H2O(l) yields Ca(OH)2(s) delta H rxn= -64.8 kJ/mol
Atomic mass of Calcium = 40
Atomic mass of Oxygen = 16
Molecular mass of CaO = 40+16 = 56
Molecular mass of H2O = 1*2 + 16 = 18
CaO + H2O = Ca(OH)2 ...
The solution provides a solution to finding the change in heat energy of water after a reaction using concepts of molecular mass and specific heat capacity.