A calorimeter contains 24.0 of water at 15. When 2.50 of (a substance with a molar mass of 66.0 ) is added, it dissolves via the reaction and the...

A calorimeter contains 24.0 of water at 15.0. When 2.50 of (a substance with a molar mass of 66.0 ) is added, it dissolves via the reactionand the temperature of the solution increases to 25.5.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.