an amount of solid barium chloride, 20.8 g, is dissolved in 100 g of water in a coffee-cup calorimeter by the reaction: bacl2 (s)  ba2 (aq) 2cl−(aq) the water is originally at 25.0 °c, and after the reaction, the temperature of the solution is 26.6 °c. what is the enthalpy change (δh) associated with the reaction as written? (cs