The reaction for formation of water vapour is as follows ;
2H2+ O2 —> 2H2O
Water vapour is in the gaseous form, at STP , 1 mol of any gas occupies 22.4 L volume
If 22.4 L occupied by 1 mol
Then amount of moles in 436 L - 1/22.4 x 436= 19.5 mol
Stoichiometry of O2 to H2O is 1:2
Amount of O2 moles reacted to formed H2O is -19.5 mol /2 = 9.75 mol
