describe how the changes would affect each of the following chemical equilibra involving gases..

2NO2(arows facing both direction) N204+HEAT
1.THE TEMPERATURE IS INCREASE
2.THE PRESSURE IS DECREASED
3.THE CONCENTRATION OF NO2 is increase
4.THE CONCENTRATION OF N2O4 IS DECRESED

This is an exercse in Le Chatelier's principle. Students get confused over this but here is what you do. Just make the reaction go so as to undo what the problem does. I'll do the first one.

2NO2 <==>N2O4 + heat.

1. We increase T. So the reaction gets hotter. The reaction doesn't like to be disturbed from equilibrium so it will shift so as to UNDO the heat. How can it do that? It must USE the heat. So it must shift to the left to use heat which is being added. N2O4 will decrease and NO2 will increase.
3. Concn NO2 is increased. So the reaction will try to UNDO the increase. How can it do that? It will shift the reaction to the right so as to USE some of the NO2 that has been added. N2O4 will increase