7. foam cup a has 36 ml of water that contain 2 moles of hcl at 20°c. foam cup b has 36 ml of water that contain 2 moles naoh of at 20°c. 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°c. calculate the enthalpy change of the reaction. the density of each solution is 1g/ml. a.-1.66 kj b.-3.31 kj c.-6.62 kj d.-13.2