Question

I need a second set of eyes!! Does this make sense?

Once glucose is placed in a baggie we placed in distilled water. We pulled a sample of water from the bottom of the beaker and added Benedict solution to it which turned it to a light blue. Adding Benedict solution to glucose tests for presence of reducing sugars that have the aldehyde functional group. – CHO. Once the Benedict solution turned glucose solution to light blue it was then heated in boiling distilled water. Positive results indicates a color change to orange proving diffusion occured. The bright red on the bottom of the tube indicates the presence of the aldehyde group. Benedict solution is a deep-blue alkaline solution because it contains copper sulfate. When mixed with glucose and heated, glucose oxidizes and gives up an electron that copper accepts and then become reduced which turns Benedict’s solution and sugar into an orange color and blue copper ion is reduced to a red copper ion. Therefore, because glucose can reduce copper in the Benedict Solution, it’s called a reducing sugar. Test was not redone. Our group and the group we compared our results with had same results and color.

Answer 1

It's good.

Following suggestions have been made.

Once glucose is placed in a baggie we placed in distilled water. We pulled a sample of water (colorless) from the bottom of the beaker and added Benedict solution (light blue color) to it which turned it to a light blue. Adding Benedict solution to glucose tests for presence of reducing sugars that have the aldehyde functional group. – CHO (or, free ketone group i.e. alpha-hydroxy ketone, too.). Once the Benedict solution turned glucose solution to light blue it was then heated in boiling distilled water. (glucose solution immediately takes the color of Benedict’s reagent when mixed with. The word “Once” seems indicating that the appearance of blue color “takes some time” or “you had to wait for few minutes for blue color to appear”). Positive results indicates a color change to orange proving diffusion occured. The bright red on the bottom of the tube indicates the presence of the aldehyde group (It is advised to thoroughly mix the Benedict’s reagent and glucose solution prior to heat. Gentle shaking of the tube while heating the reation mixture is also recommended. Therefore, the whole solution shall turn red. The red precipitate (Cu₂O) at bottom is only observed if you allow the tube to stand for longer time. But initially, appearance of red/orange color of the solution (not at bottom) indicates positive result.).

Benedict solution is a deep-blue alkaline solution because it contains copper sulfate. When mixed with glucose and heated, aldehyde group gets oxidized by accepting an O-atom from OH^- (under alkaline condition that results highly reductive enediols from reducing sugar) and gives up an electron that copper ion (Cu²⁺) accepts and then become reduced (Cu²⁺ --> Cu⁺ ; product is Cu₂O- red color) which turns Benedict’s solution and sugar into an orange color and blue copper ion (Cupric ion, Cu²⁺) is reduced to a red copper ion (Cuprous ion, Cu⁺ ; Cu₂O, cuprous oxide is brick red in color that is observed as positive test color). Therefore, because glucose can reduce copper in the Benedict Solution, it’s called a reducing sugar.

Test was not redone. Our group and the group we compared our results with had same results and color.

Note: Cu²⁺ is cupric; Cu ⁺ is cuprous.