Question

The $K_p$ for $2S{O}_{2\left(g\right)+O_{2\left(g\right)}}\rightleftharpoons 2S{O}_{3\left(g\right)}$ is $5.0at{m}^{-1}$.What is the equilibrium partial pressure of $O_2$ if the equilibrium pressure of $S{O}_2$ and $S{O}_3$ are equal?

• A. 0.2
• B. 0.3
• C. 0.4
• D. 0.1

Answer 1

The correct option is A 0.2

$2S{O}_2+O_2\to 2S{O}_3$

$K_p$ can be calculated as:

$K_p=\frac{\left[P_{S{O}_3^{2-}}\right]}{\left[P_{S{O}_2}^2\right]\times \left[P_{O_2}\right]}$

As given:

$\left[P_{S{O}_3}\right]=\left[P_{S{O}_2}\right]$

So,

$5=\frac{1}{\left[O_2\right]}$

$P_{O_2}=\frac{1}{5}$

$P_{O_2}=0.2$

So, partial pressure of oxygen will be 0.2 atm.

0.2 atm will be the partial pressure of $O_2$.