In a study of the conversion of methane to other fuels, a chemical engineer mixes gaseous CH4 and H2O in a 0.32-L flask at 1200 K. At equilibrium the flask contains 0.26 mol of CO, 0.091 mol of H2, and 0.041 mol of CH4. What is the [H2O] at equilibrium

Respuesta :

Answer: The [tex][H_{2}O][/tex] at equilibrium is 0.561 M.

Explanation:

The given data is as follows.

    Volume of flask = 0.32 L,

 No. of moles of [tex]CH_{4}[/tex] = 0.041 mol,

 No, of moles of CO = 0.26 mol,  No. of moles of [tex]H_{2}[/tex] = 0.091 mol

 Equilibrium constant, K = 0.26

Balanced chemical equation for this reaction is as follows.

     [tex]CH_{4}(g) + H_{2}O(g) \rightleftharpoons CO(g) + 3H_{2}(g)[/tex]

Hence,

              K = [tex]\frac{[CO][H_{2}]^{3}}{[CH_{4}][H_{2}O]}[/tex] ...... (1)

First, we will calculate the molarity or concentration of given species as follows.

[tex]CH_{4} = \frac{0.041}{0.32}[/tex] = 0.128 M,

[tex]CO = \frac{0.26}{0.32}[/tex] = 0.8125 M,

[tex]H_{2} = \frac{0.091}{0.32}[/tex] = 0.284 M

Therefore, using expression (1) we will calculate the [tex][H_{2}O][/tex] as follows.

     K = [tex]\frac{[CO][H_{2}]^{3}}{[CH_{4}][H_{2}O]}[/tex]

or,    [tex][H_{2}O] = \frac{[CO][H_{2}]^{3}}{[CH_{4}] \times K}[/tex]

             = [tex]\frac{0.8125 \times (0.284)^{3}}{0.128 \times 0.26}[/tex]

             = [tex]\frac{0.0187}{0.0333}[/tex]

             = 0.561 M

Thus, we can conclude that the [tex][H_{2}O][/tex] at equilibrium is 0.561 M.