Which direction would the equilibrium shift when CH4 + 2H2S = CS2 + 4H2. When decrease the concentration of dihydrogen sulfide?

The equilibrium would shift to the right, towards the products side, in order to counteract the decrease in concentration of dihydrogen sulfide. This is because according to Le Chatelier's Principle, when the concentration of a reactant is decreased, the equilibrium will shift in the direction that produces more of that reactant. In this case, decreasing the concentration of H2S would cause the equilibrium to shift towards the products side to produce more H2S.

According to Le Chatelier's principle, if the concentration of a reactant is decreased, the equilibrium will shift in the direction that produces more of that reactant. In this case, decreasing the concentration of dihydrogen sulfide will shift the equilibrium to the left, towards the formation of more CH4 and 2H2S.