A calorimeter contains 20.0 of water at 11. When 2.50 of (a substance with a molar mass of 69.

A calorimeter contains 20.0 of water at 11.5. When 2.50 of (a substance with a molar mass of 69.0 ) is added, it dissolves via the reactionand the temperature of the solution increases to 27.5.Calculate the enthalpy change, , for this reaction per mole of . Assume that the specific heat and density of the resulting solution are equal to those of water [4.18 and 1.00 ] and that no heat is lost to the calorimeter itself, nor to the surroundings.