JEE Chemistry 2025 Question with Solution

Given: The compounds are $(\text{NH}_4)_2\text{S}$, $\text{PbS}$, $\text{CuS}$, $\text{As}_2\text{S}_3$ and $\text{As}_2\text{S}_5$.

Find: Which inorganic sulphides are yellow in colour.

Examine the colour of each sulphide from the given list:

• $(\text{NH}_4)_2\text{S}$: ammonium sulphide is not yellow.
• $\text{PbS}$: lead(II) sulphide is black.
• $\text{CuS}$: copper(II) sulphide is black.
• $\text{As}_2\text{S}_3$: arsenic trisulphide is yellow.
• $\text{As}_2\text{S}_5$: arsenic pentasulphide is yellow.

Thus, the yellow sulphides are $\text{As}_2\text{S}_3$ and $\text{As}_2\text{S}_5$.

Therefore, the correct option is D.

Given: A list of inorganic sulphides is provided.

Find: The compounds among them that are yellow.

Arsenic sulphides are known for their yellow coloration and are used as yellow pigments. Hence:

• $\text{As}_2\text{S}_3$ is yellow.
• $\text{As}_2\text{S}_5$ is yellow.

The other listed sulphides do not match this colour description, because $\text{PbS}$ and $\text{CuS}$ are black, while $(\text{NH}_4)_2\text{S}$ is not yellow.

So the compounds corresponding to (D) and (E) only are correct.

Therefore, the correct option is D.