What is the reaction between glucose solution and Benedict's solution?

Answer 1

yes because the glucose molecules contain available reactive carbonyl groups- ketones or aldehydes which lose electrons (hence- reducing) to ions in the copper sulfate in Benedict's solution. a reaction between the ions and oxygen occur to create cuprous oxide which makes a brick red colour

Answer 2

Benedict's solution changes the color of glucose from blue to a yellowish orange color. This is because it causes a chemical reaction in the glucose breaking down the copper bonds in the solution. Starch can not break down the bonds in Benedict's solution.

Answer 3

Glucose contains one -CHO (aldehyde group) in its structure, this reacts with the free Cu++ ions in the Benedict's solution to give the characteristic colour 1). The reducing sugar, such as glucose, gives (donates) the Cu(II) ion 1 electron each, thereby reducing it to Cu(I)-oxide. This is only possible at pH > 9. The glucose is oxidised to gluconic acid

The full reaction is a 'coupled redox' reaction:

• oxidant: 2 Cu++ + 2 OH- + 2 e----> (Cu2O)solid + H2O
• reductant: -CHO + 3 OH- --->2e- + -COO- + 2 H2O

1) progress in colours:

1. from: blue, due to Cu++ions (with no glucose present),
2. to: green, yellow, orange, red,

   due to upcoming (Cu2O)solid precipitate and disappearing Cu++ions

3. finally turning into: brick red or brown (with high glucose present)

Answer 4

you have to heat the glucose after you put the benedict's solution in it, so that the reaction can take place properly. the solution will turn orange in colour indicating glucose as a monosaccharide.