Question

In Fehling's or Benedict's solution, a reducing sugar causes conversion of

• A. Ferric to ferrous state
• B. Ferrous to ferric state
• C. Cuprous to cupric state
• D. Cupric to cuprous state

Answer 1

The correct option is D Cupric to cuprous state

Saccharides having free aldehyde and ketone groups are known as reducing sugar. Benedict's or Fehling's solution is used to identify the reducing sugar. The sugar can reduce cupric ions of Benedict's or Fehling's solution to cuprous ion. The solution contains a blue colour alkaline solution of copper sulphate. Reducing sugar changes into insoluble reddish cuprous oxide. Thus, the correct answer is D.