①2Li(s)+ H2(g)=2LiH(s) △H=-182 kJ/mol
②2H2(g)+O(g)=2H2O1) △H=- 572 kJ/mol
③4Li(s)+O2(g) = 2Li2O(s) △H=-1196 kJ/mol
则反应2LiH(s)+O2(g)=Li2O(s)+H2O(l)的焓变为( )