Identify the inorganic sulphides that are yellow in colour: (A) (NH4)2S (B) PbS (C) CuS (D) As2S3 (E) As2S5 Choose the…

Step 1: Understand the Problem

We need to identify the color of the given inorganic sulphides. The question specifically asks for the yellow ones.

Step 2: Analyze the given sulphides

• (A) $\ce{(NH4)2S}$: Ammonium sulphide in its natural aqueous solution state is known as "yellow ammonium sulphide" (which contains polysulphides, $\ce{(NH4)2S_x}$). It is yellow in color.
• (B) $\ce{PbS}$: Lead(II) sulphide is famously a black precipitate.
• (C) $\ce{CuS}$: Copper(II) sulphide is also a black precipitate.
• (D) $\ce{As2S3}$: Arsenic(III) sulphide forms a characteristic yellow precipitate when $\ce{H2S}$ is passed through an acidic solution of $\ce{As^{3+}}$.
• (E) $\ce{As2S5}$: Arsenic(V) sulphide is also a yellow precipitate.

Step 3: Select the correct options

The yellow sulphides from the list are (A) $\ce{(NH4)2S}$, (D) $\ce{As2S3}$, and (E) $\ce{As2S5}$.

Step 4: Conclusion

Therefore, (A), (D), and (E) are the correct choices, which corresponds to option (c).

Key Points to Remember:

• Sulphides of Group II (such as $\ce{PbS}$, $\ce{CuS}$, $\ce{HgS}$, $\ce{Bi2S3}$) are generally black or dark brown.
• Group IIB elements (Arsenic, Antimony, Tin) have distinguishable colors: $\ce{As2S3}$ and $\ce{As2S5}$ are yellow, $\ce{Sb2S3}$ is orange, and $\ce{SnS2}$ is yellow.
• Yellow ammonium sulphide (YAS) is a commonly used reagent and is yellow.