Question

If 30 ml of H2 and 20 ml of o2 reacts to form water then what is left after the reaction

Answer 1

Dear student,
Reaction between H₂ and O₂ to form water is as follows:
$H_2+\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.O_2\to H_{2}O$
According to the reaction,
1 ml of H₂ reacts with 1/2 ml of O₂ form 1 ml of H₂O
So, 30 ml of H₂ will react with $\left(\frac{30}{2}\right)ml$ = 15 ml of O₂ to form 30 ml of water.

Thus, O₂ is present in excess. Hence, (20 -15 ) ml = 5 ml of O₂ is left behind.

Regards