I don't understand one of my homework questions i'm really stuck. please help!
How will the equilibrium: Heat + CH4(g) + 2H3S(g)= CS2 (g) + 4H2 (g) be affected by the following:
a) A decrease in temperature.
b) The addition of H2.
c) The removal of some CH4 (g)
d) An increase in the volume of the container.
e) The addition of a catalyst.
I assume you meant H2S.
This is a problem using Le Chatelier's Principle. I REALLY like the way textbooks write the definition; however, most students get mixed up when I quote that so here is a very simple definition of the principle. "When a system is at equilibrium and we do something to disturb the system, the system tries to undo what we've done to it." I will do some as an example and leave the rest for you.
Heat+CH4(g) + 2H2S(g)= CS2(g) + 4H2(g)
a)Notice heat is on the left. If we ADD heat to the system the system will try to undo that. How? By using up the heat we've added. How can it do that. By making the reaction shift to the right. The equation tells you that heat is used up in the reaction.
b) The addition of H2. Note H2 is on the right side so adding H2 means the system will try to use what we've added. It can do that by shifting to the left since H2 and CS2 can combine to form the reactants.
c)Remove some CH4. CH4 is on the left. Removing CH4 means the system will try to add CH4. How can it do that? By shifting to the left and making H2 and CS2 react to form CH4 and H2S (and heat).
I've done 60%; I'll leave the other 40% for you. Remember that a catalyst NEVER shifts the equilibrium and changing the volume means the pressure changes and that makes the rxn shift to the side with the smaller number of moles of gas (for increase in P) or to the larger number of moles (for a decrease in P).