Chemistry · May / June 2022 · Paper 12 · Question 22

Nitrogen dioxide, NO2, is a dark brown gas that decomposes as shown in the equation. 2NO2(g) ⇌ 2NO(g) + O2(g) dark brown colourless The diagram shows a glass flask containing a mixture of the three gases. The mixture is pale brown. [diagram of a glass flask containing NO2, NO, O2 mixture connected to an inlet for gas] More oxygen is forced into the flask. Which colour change is seen in the mixture?

1. AIt becomes a darker brown.
2. BIt becomes a paler brown.
3. CIt turns colourless.
4. DThere is no change.

As printed in the paper