posted by Johnson .
Explain, in terms of particles, concentration, and reaction rate, what you expect to happen when methane gas (CH4) and hydrogen sulfide gas (H2S) are sealed in a flask and reach a state of equilibrium.
CH4 (g) +2 H2S (g)<=> CS2 (g) + 4 H2 (g)
I would look at dGo tables in your text, calculate dGo for the reaction, use that to solve for Keq, then explain how the system reacts.
On a much less work scale, the rate at which CH4 and H2S react decreases with time while the rate at which CS2 and H2 react increases with time. There is a point at which the forward reaction and the reverse direction are equal and this is equilibrium. This should serve to get you started.