Sulphur colloid is prepared by

Options

A. Mechanical dispersion
B. Oxidation
C. Electrical dispersion
D. Reduction

Explanation

To prepare a sulfur colloid, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Preparation of Sulfur Colloid**:
Sulfur colloid can be prepared through various methods, but one common method is through oxidation.

2. **Identifying the Oxidizing Agent**:
In this case, bromine (Br2) acts as the oxidizing agent. It oxidizes hydrogen sulfide (H2S) to produce sulfur colloid.

3. **Chemical Reaction**:
The chemical reaction can be represented as follows:
\[ 2 H_2S + Br_2 \rightarrow 2 HBr + S \]
Here, hydrogen sulfide (H2S) is oxidized by bromine (Br2) to form hydrogen bromide (HBr) and sulfur (S).

4. **Formation of Colloid**:
The sulfur produced in this reaction forms a colloidal solution, which is a stable dispersion of fine sulfur particles in a liquid.

5. **Final Colloid Preparation**:
The resulting colloidal sulfur can be stabilized and used in various applications, such as in pharmaceuticals and as a pigment.

### Summary:
Sulfur colloid is prepared by the oxidation of hydrogen sulfide (H2S) using bromine (Br2).

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