Consider the equilibrium between colorless, gaseous N2O4 and brown, gaseous NO2?

Question

N2O4(g) <-> 2NO2(g)

The forward reaction involves breaking the N-N bond and is endothermic. If the temperature of a system at equilibrium is raised, willl the intensity of the brown color increase, decrease, or remain unchanged?

I think this has something to do with Le Chatelier's Principle, but I still can't determine the answer. Thanks for the help everybody! Oh and please don't answer if you can't answer the question :)

Answer 1

Basically what Le Chatelier's Principle is trying to say is that if a system in equilibrium experiences a change, then it will try and counteract that change.

In this case, the excess heat is the change experienced. To counteract the excess heat, some of it must be absorbed. Thus, the endothermic reaction in which heat is absorbed will occur at a higher rate than the other reaction.

The endothermic reaction is the forward reaction. (Equilibrium shifts to the right.) Thus, more N2O4 will be converted to NO2 than the other way round, resulting in less brown-coloured N2O4 molecules in the system. Therefore, the intensity of the colour will decrease.

:) hope you find this useful!

Answer 2

No2 N2o4 Equilibrium

Answer 3

the brown color comes from the color of NO2.Because the reaction is endothermic,when the temperature is raised,that means you supply more energy to the reaction and the equilibrium will shift to the right.That means that more NO2 gas is produced and therefore the intensity of the brown color will increase

Answer 4

so, if it's endothermic, then heat must be put into the reaction. if you put more heat into the reaction, more products will be produced. as more products are produced, the gases become browner.

it has everything to do with le chatelier. i suggest drawing in the heat symbol to help you.

delta H +N2O4 <--> 2NO2
add more heat, reaction shifts to the right