Answer
$\frac{[CS2][H2]^{4}}{[CH4][H2S]^{2}}$
Work Step by Step
The equilibrium constant, k, is defined as the products to the power of the coefficient over the reaction to the power of the coefficient. In this case, the products are CS2 and H2. H2 has a coefficient of four so it is raised to the fourth power. CS2 has a coefficient of one so it is raised to the first power. The reactants CH4 has a coefficient of one so it is raised to the first power. The other reactant H2S has a coefficient of 2 rasing it to the second power. Therefore, the k value is $\frac{[CS2][H2]^{4}}{[CH4][H2S]^{2}}$
