Question

A mixture of hydrogen and oxygen has volume 2000 \(cm^3\), temperature 300 K, pressure 100 kPa and mass 0.76 g. The ratio of number of moles of hydrogen to number of moles of oxygen in the mixture will be:[Take gas constant R = 8.3 \(JK^{–1}\) \(mol^{–1}\)]

• A. \(\frac{1}{3}\)
• B. \(\frac{3}{1}\)
• C. \(\frac{1}{16}\)
• D. \(\frac{16}{1}\)

Answer 1

The Correct Option is B

\(P_1V = n_1RT\)

\(P_2V = n_2RT\)

\(⇒ (100 kPa) V = (n_1 + n_2)RT\)

\(⇒n_1+n_2=\frac{(100 kPa)(2000 cm)^3)}{8.3×300}….(1)\)

Also, \(n_1 × 2 + n_2 × 32 = 0.76 ….(2)\)

Solving (1) and (2),

\(n_1 = 0.06\)

\(n_2 = 0.02\)

\(⇒ \frac{n_1}{n_2} = 3\)

Hence, the correct option is (B): \(\frac{3}{1}\)