Question

When it’s really cold in Little Rock, the sky can look clear and blue. The same sky in July might look brown and gross. In both cases the many cars in the city are producing significant amounts of nitrogen oxides. Describe these observations in terms of LeChatelier’s principle.

Answer 1

First, let us define the reactions:

N2O4 + heat <=> 2NO2

N2O4 = colorless; mix = brown; NO2 = red/brown

Then... recall the equilibrium

let us state the Le Chatelier principle which deals with changes in an equilibrium:

The statement is as follows:

If any equilibrium is disturbed, that is, change in conditions such as P,T, concentration, partial pressure, etc.., the system will counterbalance such change in order to favour the system's equilbirium.

In July, we have high Temperatures, therefore, this implies there is more Energy avialable for the reaction, Then NO2 will be produced

Since NO2 is red/brown, then expect the "brown and gross look"

In winter; we lower temperature, therefore, the N2O4 reverse reaciton occurs

Since N2O4 is colorless, we can see a "better" view" or "much clear and blue" sight.