Correct answers are:
- Solids can diffuse in liquids. Think of a sugar cube sitting at the bottom of a cup of tea.
- Liquids can diffuse in liquids. Think of a drop of food colouring in water
- It is the process of intermingling atoms from one substance into another.
The other answers are <em>incorrect</em> because:
- Gas molecules are far apart and diffuse rapidly.
- A solid can diffuse into another solid. Pure lead can diffuse into gold, and pure gold can diffuse into lead.
Explanation:
According to Le Chatelier's principle, any disturbance caused in an equilibrium reaction will shift the equilibrium in a direction that will oppose the change.
As the given reaction is as follows.

(a) When increase the temperature of the reactants or system then equilibrium will shift in forward direction where there is less temperature. It is possible for an endothermic reaction.
Thus, formation of
will increase.
- (b) When we decrease the volume (at constant temperature) of given reaction mixture then it implies that there will be increase in pressure of the system. So, equilibrium will shift in a direction where there will be decrease in composition of gaseous phase. That is, in the backward direction reaction will shift.
Hence, formation of
will decrease with decrease in volume.
- When we increase the mount of
then equilibrium will shift in the direction of decrease in concentration that is, in the forward direction.
Thus, we can conclude that formation of
will increase then.