`SnCl_(2)` is used

Options

A. as a mordant in dyeing
B. as an oxidising agent
C. good thermal insulation
D. in the preparation of colloidal gold

Explanation

To solve the question regarding the uses of SnCl₂ (stannous chloride), we can break it down step by step:

### Step 1: Identify the compound
SnCl₂ is known as stannous chloride, where "Sn" represents tin (tin is in the carbon family) and "Cl" represents chlorine.

### Step 2: Determine the oxidation state of tin
In SnCl₂, the oxidation state of tin (Sn) is +2. This is because each chlorine atom (Cl) has an oxidation state of -1, and with two chlorine atoms, the total negative charge is -2. Therefore, to balance this, tin must have a +2 charge.

### Step 3: Analyze the properties of SnCl₂
- SnCl₂ is known to act as a reducing agent because it can convert from the +2 oxidation state to a +4 oxidation state (Sn⁴⁺). This means it can donate electrons to other substances.
- It is also used as a mordant in dyeing processes, which means it helps fix dyes to fabrics.
- Additionally, SnCl₂ has applications in thermal insulation and in the preparation of colloidal gold.

### Step 4: Evaluate the options given in the question
The question asks for the uses of SnCl₂:
- **As a mordant in dyeing**: True
- **As an oxidizing agent**: False (it acts as a reducing agent)
- **Good thermal insulation**: True
- **In the preparation of colloidal gold**: True

### Step 5: Conclusion
Based on the analysis, the correct options for the uses of SnCl₂ are:
- A (as a mordant in dyeing)
- C (good thermal insulation)
- D (in the preparation of colloidal gold)

### Final Answer:
The correct uses of SnCl₂ are A, C, and D.

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