Question

Which of these sulfides is not black?

• A. CuS
• B. PbS
• C. Ag\(_2\)S
• D. CdS

Hint:

Cadmium sulfide (CdS) is yellow in color and is commonly used as a pigment. All other metal sulfides listed (CuS, PbS, Ag\(_2\)S) are black in color.

Answer 1

The Correct Option is D

The color of metal sulfides depends on the metal ion and the nature of the compound. 
Most transition metal sulfides are black due to their ability to absorb a wide range of wavelengths. 
Let's review the color of each sulfide: 
CuS (Copper sulfide): Black in color. 
PbS (Lead sulfide): Black in color, often formed in qualitative analysis. 
Ag\(_2\)S (Silver sulfide): Black precipitate, tarnishes silver items. 
CdS (Cadmium sulfide): Yellow in color, not black. It is often used as a yellow pigment (cadmium yellow).
Hence, among the options, only Cadmium sulfide (CdS) is not black.