ANS:C - NH₂CONHCONH₂

NH2CONHCONH2 represents the chemical formula for biuret. Biuret is an organic compound derived from urea and is often produced as an intermediate compound during urea metabolism. Here's a breakdown of the formula:

• 𝑁𝐻2NH2​: This represents an amino group, consisting of one nitrogen atom (N) bonded to two hydrogen atoms (H).
• 𝐶𝑂CO: This represents a carbonyl group, consisting of a carbon atom (C) double-bonded to an oxygen atom (O).
• 𝑁𝐻NH: This represents another amino group.
• 𝐶𝑂𝑁𝐻2CONH2​: This is the amide group, which consists of a carbonyl group (𝐶𝑂CO) bonded to an amino group (𝑁𝐻2NH2​).

When biuret is formed, two molecules of urea (𝑁𝐻2𝐶𝑂𝑁𝐻2NH2​CONH2​) undergo a condensation reaction, resulting in the elimination of a molecule of ammonia (𝑁𝐻3NH3​). This reaction forms a peptide-like bond between the two urea molecules, leading to the formation of biuret (𝑁𝐻2𝐶𝑂𝑁𝐻𝐶𝑂𝑁𝐻2NH2​CONHCONH2​). Biuret is often used in chemical analysis as a reagent to detect the presence of proteins. It forms a violet-colored complex with copper ions (the biuret reaction), which is used as a qualitative test for the presence of proteins in biological samples.