Question

A mixture of gases contains $H_2$ and $O_2$ gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two gases in the mixture?

• A. 16 : 1
• B. 2 : 1
• C. 1 : 4
• D. 4 : 1

Answer 1

Answer: (D)

4 : 1

Answer 2

The correct answer is D:$4:1$
A mixture of gases contains hydrogen $(H2)$ and oxygen $(O2)$ in a weight-to-weight ratio of $1:4$. If we have $100grams$ of hydrogen and $400 grams$ of oxygen, we can calculate the number of moles for each gas based on their respective molar masses.
The number of moles of hydrogen present is: $\frac{100 g}{2 g/mol} = 50 moles$.
The number of moles of oxygen present is $\frac{400 g}{32 g/mol} = 12.5 moles.$
$\therefore$The molar ratio of the two gases in the mixture is 50 moles of hydrogen to 12.5 moles of oxygen:$\frac{50}{12.5}$; which simplifies to 4:1.