Question

In the reaction N2O4(g) 2NO2(g), what changes in color would you expect as pressure is increased at constant temperature?

Answer 1

Answer:

Brown color of the solution decreases

Explanation:

$NO_2$ is brown in color whereas $N_2O_4$ is colorless.

Equilibrium reaction between $NO_2$ and $N_2O_4$ is as follows:

$2NO_2\leftrightharpoons N_2O_4$

As per the Le Chatelier's principle, if pressure of a equilibrium is increased, the equilibrium will shift in the direction having fewer no. of moles of gases.

In the given equilibrium, $NO_2$ side has more no. of moles. So on increasing pressure, equilibrium will shift towards the side of $N_2O_4$ or more formation of $N_2O_4$ will take place.

Therefore, more $NO_2$ will decompose that will decrease the brown color of the solution as $N_2O_4$ is colorless.