text: chemistry! help plz!? in equilibrium state, let's say in an exothermic reversible reaction, how does the following affect the rate of reaction and the composition of the mixtures?  and also let's say the eq is:  n2 + 2h2 = 2nh2(exothermic reaction)  1. adding a catalyst.  2. adding a positive catalyst.  3. adding a negative catalyst.  4. using high pressure.  5. using low pressure.  6. using high temperature.  7. using low temperature.  will the same thing happen for an endothermic reversible reaction?  thanks! answer plz! any related website url will also help! its very important! 1. adding a catalyst does not change the equilibrium. it simply speeds up the rate at which equilibrium is reached.  4. there is a higher pressure on the lhs than on the rhs ( 3 molecules as compared to 2 molecules). using le chatelier's principle if pressure is inc. equilibrium will try to reduce the pressure and forward rctn takes place.  5. opposite of 4. backwards rctn takes place.  6. if the forward rctn. is exothermic the equilibrium will shift to the reaction which absorbs heat thus cooling down the system. so the endothermic reaction, in this case the backwards rctn will take place.  7. opposite of 6. forward rctn takes place.  if the forward reaction is endothermic 6 and 7 would change