Foam cup a has 36 ml of water that contains 2 moles of hcl at 20 degrees celsius. foam cup b has 36 ml of water that contains 2 moles of naoh at 20 degrees celsius. the contents of foam cup a are added to foam cup b and a chemical reaction occurs. the final temperature of the contents of cup b is 31 degrees celsius. i need to calculate the enthalpy change of the reaction. the density of both solutions is 1 g/ml.