NEET BIOLOGY

Detailed explanation-1: -Sucrose indirectly produces a positive result with Benedict’s reagent if heated with dilute hydrochloric acid prior to the test, although after this treatment it is no longer sucrose.

Detailed explanation-2: -It can be noted that Benedict’s test can also be used to check for the presence of glucose in a urine sample. Since this test detects any aldehydes and -hydroxy ketones and glucose is an aldose whose open-chain forms an aldehyde group, the test yields a positive result when glucose is present in the analyte.

Detailed explanation-3: -Interpreting Benedict’s Reagent Results The “hotter” the final color of the reagent, the higher the concentration of reducing sugar. In general, blue to blue-green or yellow-green is negative, yellowish to bright yellow is a moderate positive, and bright orange is a very strong positive.

Detailed explanation-4: -A positive test is a dark red precipitate and is evidence of a reducing monosaccharide. In Seliwanoff’s test, a dehydration reaction is involved. Seliwanoff’s reagent contains a non-oxidizing acid (HCl) and resorcinol.