Why should ketoses not react with benedict’s reagent? think about the type of reaction and be specific.

There's no reducing sugar.

Explanation:

The Benedict test is another of the oxidation reactions, which, as we know, helps us to recognize reducing sugars, that is, those compounds that have their free anomeric OH, such as glucose, lactose or maltose or cellobiose, in the Benedict reaction can reduce the Cu2 + that presents a blue color, in an alkaline medium, the cupric ion (given by cupric sulfate) is able to be reduced by the effect of the aldehyde group of sugar (CHO) to its Cu + form. This new ion is observed as a red brick precipitate corresponding to cuprous oxide (Cu2O), which precipitates from the alkaline solution with a red-orange color, this precipitate is considered as evidence that there is a reducing sugar.

Benedict's reagent is composed of:

*Cupric sulfate.

*Sodium citrate.

*Anhydrous sodium carbonate.

The evidence of Benedict's reaction is the formation of the precipitate Ion Cuprous (Cu2O).

It means:

Cu+2 > Cu+1

Then, if we don't have a reducing sugar, the reactive is not going to react with our sample.