Statement I: Cadmium sulphide is yellow coloured

Statement II: The d–d transition does not take place in this compound

If both Statement I and statement II are true but statement II is not the correct explanation for statement I

The answer is (2) Both Statement I and Statement II are true but statement II is not the correct explanation for statement I.

Statement I is correct because cadmium sulphide is yellow colored due to the presence of sulphur. Sulphur has a partially filled d-orbital, which can absorb energy from visible light and cause the compound to appear yellow.

Statement II is also correct because the d–d transition does take place in cadmium sulphide. However, the d–d transition is not the only reason why cadmium sulphide is yellow. The absorption of energy from visible light by the partially filled d-orbital is the dominant reason why the compound is yellow.

Therefore, the correct answer is (2).

Here is a table of the reasons why cadmium sulphide is yellow:

Statement II is not the correct explanation of Statement I because the d–d transition is not the only reason why cadmium sulphide is yellow.