What is the net ionic equation for the reaction of 0.5M solution of sodium hypochlorite and 0.5M solution of sodium thiosulfate? Calculate the enthalpy change. I have a very terrible chemistry teacher. I haven't learned how to write ionic equations yet, but he wants this assignment for marks. Besides that, enthalpy change, we've done somewhat of it. But we don't have the numbers for the bond energies. I don't even know the equation yet so i really don't know how to solve this at all. And is there a difference between the enthalpy change and standard heat of formation? I looked up a chart for Sodium hypochlorite, but it doesn't say the Hf of the it. I am really stuck here. Please help me with this whole problem.