text: chemistry help? a student added ca to water and measured the increase in temperature to determine dh(rxn) for the equation ca (s) + 2h2o (l) ----> ca(oh)2 (aq) +h2 (g) a sample of 0.5271 g of ca was added to 100.0 ml of distilled water in a styrofoam cup.  the change in temperature was +9.3 c.  the density of the solution was 1.005 g/ml and the specific heat of the solution was 4.18 j/g*c.  the heat capacity of the cup was 21.0 j/c.  a)  calculate the heat of reaction per gram of calcium. b)  calculate the heat of reaction per mole of calcium. http://chemistry.about.com/  http://chemistry.about.com/od/homeworkhelp/