When 0.627 g of Ca metal is added to 200.0 mL of 0.500 M HCl(aq), a temperature increase of 102C is observed.

Assume the solution's final volume is 200.0 mL, the density is 1.00 g/mL, and the heat capacity is 4.184 J/gC.

The molar heat of reaction, H rxn, for the reaction of

Ca(s) + 2H+(aq) Ca2+(aq) + H2(g)

is ____kJ/mol.