Alkali metals can be extracted form their salts by

Options

A. Reduction with carbon
B. Electrolysis of fused halides
C. Electrolysis of used halides
D. Reduction with aluminum

Answer

To solve the question "Alkali metals can be extracted from their salts by," we will analyze the options provided and determine the correct method of extraction based on the properties of alkali metals.

### Step-by-Step Solution:

1. **Understanding Alkali Metals**:
- Alkali metals (Li, Na, K, Rb, Cs) are highly reactive and possess unique properties such as being strong reducing agents and highly electropositive.

2. **Analyzing the Extraction Methods**:
- **Option A: Reduction with Carbon**:
- This method is generally used for extracting metals that are less reactive. Alkali metals cannot be extracted this way due to their strong reducing nature. Hence, this option is incorrect.

- **Option B: Electrolysis of Fused Halides**:
- This method involves the electrolysis of molten salts (usually chlorides) of alkali metals. Due to their high reactivity, alkali metals can be successfully extracted using this method. This option is correct.

- **Option C: Electrolysis of Used Halide**:
- This option seems to be a typographical error or misstatement. It does not represent a valid extraction method and is therefore incorrect.

- **Option D: Reduction with Aluminium**:
- Alkali metals are highly electropositive and cannot be reduced by aluminium. Thus, this method is also incorrect.

3. **Conclusion**:
- Based on the analysis, the only viable and successful method for extracting alkali metals from their salts is **Option B: Electrolysis of fused halides**.

### Final Answer:
Alkali metals can be extracted from their salts by **Electrolysis of fused halides**.

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