If 30 ml of `H_2` and 20 ml of `O_2` react to form water, what is left at the end of the reaction ?

Options

A. 10 ml of `H_2`
B. 5 ml of `H_2`
C. 10 ml of `O_2`
D. 5 ml of `O_2`

Answer

D

Explanation

`underset("2vol")(2H_2) + underset("1 vol")(O_2) to 3H_2O`
2 vol. of `H_2` react with 1 vol of `O_2` to give water
` therefore ` 30 ml of `H_2` will react with 15 ml of `O_2`
Hence of `H_2` is a limiting reactant
vol of `O_2` left unreacted = 20 - 15 = 5 ml