Step1 Reverse the 2nd equation and add to the first equation Step2 C2H4(g) + H2O(l)----> C2H5OH(l) ;Change of H= -1411.1+1367.5= 43.6 kj Step3 Reactants Products Solution Step1 Reverse the 2nd equation and add to the first equation Step2 C2H4(g) + H2O(l)----> C2H5OH(l) ;Change of H= -1411.1+1367.5= 43.6 kj Step3 Reactants Products.