Fehling’s solution –B is-

Options

A. `NH_(4)`OH
B. `Cu(OH)_(2)`
C. CuO
D. `Cu_(2)`O

Answer

**Step-by-Step Solution:**

1. **Understanding Fehling's Solution**: Fehling's solution is a chemical reagent used to test for the presence of reducing sugars and aldehydes. It consists of two separate solutions known as Fehling's A and Fehling's B.

2. **Components of Fehling's Solution**:
- **Fehling's A**: This is an aqueous solution of copper(II) sulfate (CuSO₄). It is typically deep blue in color due to the presence of copper ions.
- **Fehling's B**: This solution is colorless and is made up of potassium sodium tartrate (also known as Rochelle salt) dissolved in water, along with a strong alkali, usually sodium hydroxide (NaOH).

3. **Preparation of Fehling's Solution**: To prepare Fehling's solution, you mix equal volumes of Fehling's A and Fehling's B. The resulting solution is used to test for aldehydes, which reduce the copper(II) ions to copper(I) oxide, forming a red precipitate.

4. **Identifying Fehling's B**: Based on the components discussed, Fehling's B is specifically the aqueous solution of potassium sodium tartrate (Rochelle salt) combined with sodium hydroxide.

5. **Conclusion**: Therefore, the correct answer to the question "Fehling’s solution B is-" is that it is an aqueous solution of potassium sodium tartrate (Rochelle salt) combined with sodium hydroxide.

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