Question

What is the total number of black-colored sulfides among ${\mathrm{Ag}}_2\mathrm{S},{\mathrm{Bi}}_2{\mathrm{S}}_3,\mathrm{CoS},\mathrm{CuS},\mathrm{HgS},\mathrm{MnS},\mathrm{NiS},\mathrm{PbS},\mathrm{and}{\mathrm{SnS}}_2$.

• A. Two
• B. Four
• C. Six
• D. Eight

Answer 1

The correct option is C

Six

The explanation for correct option:

C. Six

1. Silver sulfide:

• The chemical formula for Silver sulfide is ${\mathrm{Ag}}_2\mathrm{S}$.
• It is greyish black in color.

2. Bismuth (III) sulfide:

• The chemical formula for Bismuth (III) sulfide is ${\mathrm{Bi}}_2{\mathrm{S}}_3$.
• It is dark brown in color in its crystalline form but appears black in color white precipitation.

3. Cobalt sulfide:

• The chemical formula for Cobalt sulfide is $\mathrm{CoS}$.
• It is black in color.

4. Copper monosulfide:

• The chemical formula for Copper monosulfide is $\mathrm{CuS}$.
• It is black in color.

5. Lead (II) sulfide:

• The chemical formula for lead (II) sulfide is $\mathrm{PbS}$.
• It is black in color.

6. Mercury sulfide:

• The chemical formula for Mercury sulfide is $\mathrm{HgS}$.
• It is found in red as well as black in color.

Thus, there is a total of six sulfides that are black in color.

The explanation for incorrect options:

The other sulfides are discussed below:

1. Manganese(II) sulfide

• The chemical formula for Manganese(II) sulfide is $\mathrm{MnS}$.
• It is found in red, green, brown, and pink colors.

2. Nickel sulfide:

• The chemical formula for Nickel sulfide is $\mathrm{NiS}$.
• It is a colorless sulfide.

3. Tin(IV) sulfide:

• The chemical formula for Tin(IV) sulfide is ${\mathrm{SnS}}_2$.
• It is a golden-yellowish solid.

Thus, options A, B, and D are incorrect. Hence, the correct option is C i.e. Six.