[10:58am]: Wn 4.5g of liquid water was formed by burning hydrogen gas in oxygen,-72kj of heat was given off.calc d standad heat formation of water

Answer 1

2H2 + O2 ==> 2H2O + heat
So 4.5 g gives 72 kJ, heat for the reaction above is
-72 kJ x 36 g/4.5 g = -576 kJ. That's for 2 mols so for 1 mole is it -576/2 = ?

Answer 2

-288kJ