Question

Fehling's solution is a mixture of:

• A. Copper sulfate and sodium hydroxide
• B. Sodium hydroxide and potassium cyanide
• C. Copper sulfate and potassium cyanide
• D. Copper sulfate and sodium tartrate

Hint:

Fehling's solution is commonly used to detect reducing sugars, and the reaction is based on the reduction of copper(II) ions.

Answer 1

The Correct Option is A

Fehling's solution is used to test for reducing sugars. It is a mixture of two solutions: - Fehling's solution A: A solution of copper(II) sulfate (\( \text{CuSO}_4 \)). - Fehling's solution B: A solution of sodium hydroxide (\( \text{NaOH} \)) and sodium tartrate. When these two solutions are mixed together, they form a blue complex. The presence of a reducing sugar will reduce the copper(II) ions to copper(I) ions, resulting in the formation of a red precipitate of copper(I) oxide. Thus, the correct mixture is copper sulfate and sodium hydroxide, and the answer is (A).