devarshi-dt-logo

Question:

A mixture of gases contains H2 and O2 gases in the ratio of 1:4 (w/w). What is the molar ratio of the two gases in the mixture?

16:1

1:4

4:1

2:1

Solution:

A mixture of gases contains H2 and O2 gases in the ratio of 1:4 (w/w).
Let 100g of hydrogen and 400g of oxygen are present.
The molar masses of hydrogen and oxygen are 2g/mol and 32g/mol respectively.
The number of moles of hydrogen present are 100/2 = 50 mol.
The number of moles of oxygen present are 400/32 = 12.5 mol.
The molar ratio of the two gases in the mixture is 50:12.5 or 4:1.