nmdcat.online
BIO NMDCAT Carbohydrates
nmdcat.online June 27, 2026

In Benedict’s test, a positive result for a reducing sugar is indicated by the formation of a brick-red precipitate of

A. Copper(I) oxide (Cu₂O)
✓
B. Copper(II) sulfate (CuSO₄)
C. Silver oxide (Ag₂O)
D. Lead acetate (Pb(C₂H₃O₂)₂)

📝 Explanation

The free aldehyde or ketone group of a reducing sugar reduces the blue Cu²⁺ ions (cupric) in Benedict's reagent to Cu⁺ ions (cuprous). These precipitate out of the alkaline solution as an insoluble brick-red solid, copper(I) oxide (Cu₂O).

📖 Additional Information

  • Copper(I) oxide (Cu₂O)
  • Copper(II) sulfate (CuSO₄)
  • Silver oxide (Ag₂O)
  • Lead acetate (Pb(C₂H₃O₂)₂)

The free aldehyde or ketone group of a reducing sugar reduces the blue Cu²⁺ ions (cupric) in Benedict's reagent to Cu⁺ ions (cuprous). These precipitate out of the alkaline solution as an insoluble brick-red solid, copper(I) oxide (Cu₂O).

🔗 Share This Question

Facebook Twitter LinkedIn WhatsApp

🧭 Navigate Questions

Previous Question

The function of cellulose as a structural polysaccharide in plant cell walls is directly related to its

Next Question

The formation of a glycosidic bond during polysaccharide synthesis is a classic example of a

Back to All Questions

🔗 Related MCQs

An increase in the incidence of ectopic pregnancies within a population can often be epidemiologically correlated with a prior increase in the prevalence of which sexually transmitted disease?
July 16, 2026
In the life cycle of Herpes Simplex Virus 2 (HSV-2), the virus travels along nerve fibers to reach the sensory ganglia. The cellular mechanism responsible for this retrograde transport utilizes:
July 16, 2026
A defining characteristic of the lesions associated with the secondary stage of syphilis is that they:
July 16, 2026
The causative agent of genital herpes, HSV-2, is enveloped. The biological significance of this viral envelope in the context of transmission is that it makes the virus:
July 16, 2026
The structural basis for the severe cardiovascular complications seen in tertiary syphilis, such as aortic aneurysms, is the chronic inflammation and destruction of:
July 16, 2026

Categories

View all →