Question

What will be the total pressure of mixture formed by mixing 8 g O₂ and 4 g H₂ at 27°C in a flask whose volume is 1 dm³?

Answer 1

Number of moles of oxygen

\((n_1) = \frac{\text{mass} \ \text{of} \ \text{oxygen}}{\text{molar}\ \text{mass}}\)

\( = \frac{8\ g}{32\ g\ mol^{-1}} = 0.25\ mol\)

Number of moles of H₂ 

\((n_2) = \frac{\text{mass}\ \text{of}\ \text{Hydrogen}}{\text{molar}\ \text{mass}}\)

\( = \frac{4\ g}{2\ g\ mol^{-1}} = 2\ mol\)

Partial pressure of O₂ 

_{\((Po_2) = \frac{n_1RT}{V}\)}

_{\( = \frac{0.25\times 0.83\times 300}{1dm^3}\)}

= 6.225 bar

Partial pressure of H₂ 

_{\((P_{H_2}) = \frac{n_2RT}{V}\)}

_{\( = \frac{2\times 0.083\times 300}{1dm^3}\)}

= 49.8 bar

Total pressure PTotal = PO₂ + PH₂

= 6.225 + 49.8 

= 56.025 bar