Hi, I'm trying to solve this question for chemistry, but have been going round in circles and can't get my head around it. I would be super grateful if anyone could help.2Li(s) 2H2O(l) → 2Li (aq) 2OH−(aq) H2(g)Calculate the standard enthalpy change for this reaction (above) using the following data: ∆Hf [LiOH(s)] = −487kJmol−1∆Hf [H2O(l)] = −286kJmol−1∆Hf [Li(s)] = 0kJmol−1LiOH(s) aq → Li (aq) OH−(aq) ∆H = − 21kJmol−1