Answer: The
at equilibrium is 0.561 M.
Explanation:
The given data is as follows.
Volume of flask = 0.32 L,
No. of moles of
= 0.041 mol,
No, of moles of CO = 0.26 mol, No. of moles of
= 0.091 mol
Equilibrium constant, K = 0.26
Balanced chemical equation for this reaction is as follows.

Hence,
K =
...... (1)
First, we will calculate the molarity or concentration of given species as follows.
= 0.128 M,
= 0.8125 M,
= 0.284 M
Therefore, using expression (1) we will calculate the
as follows.
K = ![\frac{[CO][H_{2}]^{3}}{[CH_{4}][H_{2}O]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BCO%5D%5BH_%7B2%7D%5D%5E%7B3%7D%7D%7B%5BCH_%7B4%7D%5D%5BH_%7B2%7DO%5D%7D)
or, ![[H_{2}O] = \frac{[CO][H_{2}]^{3}}{[CH_{4}] \times K}](https://tex.z-dn.net/?f=%5BH_%7B2%7DO%5D%20%3D%20%5Cfrac%7B%5BCO%5D%5BH_%7B2%7D%5D%5E%7B3%7D%7D%7B%5BCH_%7B4%7D%5D%20%5Ctimes%20K%7D)
= 
= 
= 0.561 M
Thus, we can conclude that the
at equilibrium is 0.561 M.