Question

michael has tested 4 different solutions of variable glucose concentration with benedict reagent. what are the possible explanations for the result observed in tube c? select all that apply a. the solution added to tube c did not contain simple sugar. b. tube c was contaminated by the contents of one of the other tubes. c. tube c was not heated for the correct amount of time.

Explanation:

Benedict's reagent reacts with reducing sugars (including simple sugars like glucose) to produce a color - change upon heating. A blue color (as in Tube C) indicates a negative result. If the solution did not contain simple sugar, no reaction would occur (A). Incorrect heating can prevent the reaction from taking place properly (C). Contamination from other tubes is less likely to cause a negative result if the tube was supposed to have a positive reaction, as contamination would likely introduce more reducing sugars or other reactive substances rather than cause a negative result.

Answer:

A. The solution added to Tube C did not contain simple sugar.
C. Tube C was not heated for the correct amount of time.