Question

A student is performing a Benedict’s test on an unknown substance. He adds the reagent (the chemical required to make a color change), and nothing happens. What can he conclude? A- The substance is glucose-based. B- The substance is not glucose-based. C- The test was inconclusive because he needed to also test with iodine or vinegar. D- The test was inconclusive because he forgot to add heat.

Answer 1

The correct conclusion is B- The substance is not glucose-based.

In a Benedict's test, a positive result (color change) indicates the presence of reducing sugars, such as glucose. If there is no color change after adding the Benedict's reagent, it suggests that the substance being tested does not contain reducing sugars. While it's true that other factors (like not applying heat) could affect the outcome, the absence of a color change specifically indicates that the substance is not glucose-based.