Question

The pictures are in backwards order, but that is the question I'm struggling with figuring out how to solve.

Answer 1

An equilibrium constant is the ratio between the concentration of products and reactants, considering their stoichiometric numbers. In a general equation, for example:

$aA\text{ + bB }\rightleftarrows\text{ cC + dD}$

the equilibrium constant would be:

$K_c=\frac{\lbrack C\rbrack^c\times\lbrack D\rbrack^d}{\lbrack A\rbrack^a\times\lbrack B\rbrack^b}$

(where [C] = product C concentration, [D] = product D concentration etc.)

Considering that definition and the reaction given in the question, we could write the equilibrium constant as:

$K_c=\frac{\lbrack CH_3OH\rbrack^{}}{\lbrack CO_{}\rbrack^{}\times\lbrack H_2\rbrack^2}$

Note that the coefficient for both CH3OH and CO2 is 1, so we don't need to show it on the Kc formula.

Therefore, the numerator would be [CH3OH] and the denominator would have the terms [CO] and [H2]^2.