Answer: 0.9704 moles of [tex]O_2[/tex] will react when 0.6469 moles of water are formed.
Explanation:
The balanced chemical reaction is:
[tex]2H_2S+3O_2(g)\rightarrow 2SO_2+2H_2O[/tex]
According to stoichiometry :
2 moles of [tex]H_2O[/tex] are formed from = 3 moles of [tex]O_2[/tex]
Thus 0.6469 moles of [tex]H_2O[/tex] are formed from =[tex]\frac{3}{2}\times 0.6469=0.9704moles[/tex] of [tex]O_2[/tex]
Thus 0.9704 moles of [tex]O_2[/tex] will react when 0.6469 moles of water are formed.