Question

at this point, the tubes all contain unknown solutions and amylase that has reacted for 30 minutes. you added benedict reagent, and the unknown solutions are still light blue, indicating no simple sugars are present. which of the following is/are possible reason(s) for a negative result in this case? select all that apply. a. the samples are not heated yet. b. unknown solutions were mixed incorrectly. c. all unknown solutions are water.

Explanation:

• A: Heating is often required for Benedict's reagent reactions with reducing sugars. If not heated, a negative result can occur.
• B: Incorrect mixing can prevent proper interaction between the reagent and the sample, leading to a negative result.
• C: If the solutions are just water, there will be no reaction with Benedict's reagent for simple - sugars detection.

Answer:

A. The samples are not heated yet.
B. Unknown solutions were mixed incorrectly.
C. All unknown solutions are water.