How can you tell by using Benedicts solution and iodine to seewhat kind of sugar it is?

Answer 1

The test for a reducing sugar using benedicts solution is by, first making a colour chart, using various KNOWN concentrations of glucose situations, if available.

Then use the unknown substance and add benedicts solution and boil, a red precipitate should appear and the "redder" it is, the stronger the concentration.

You can then filter off the precipitate and place the remaining liquid into a cuvette and pass through a colorimeter, on a red filter, the more light that passes through, the sronger the concentration. Compare this solution to your colour chart to help you determine the concentration of the reducing sugar.

Thanks :)

steph :)

Answer 2

Firstly iodine is used for testing for the presence of starch in a sample and has nothing to do with sugars(Turns blue/black in the presence of starch).

Benedict's Solution can be used to test for a reducing sugar or a non-reducing sugar:

For reducing sugar:

Add an equal volume of Benedict's solution to a sample and heat the mixture in a water bath for 10mins at 80 degrees c. If the solution turns from blue to orange (orange precipitate should form) a REDUCING sugar is present.

For Non-Reducing Sugar:

Carry out the test above, if the solution stays blue, add HCL and boil the solution, then allow it to cool and ad NaOH. Add Benedict's Solution to the mixture again and if it turns orange a NON - REDUCING sugar is present.

PS Benedict's Test is a qualitative test and partially quantitative as the the amount of precipitate formed is relative to the amount of reducing sugar/non reducing sugar present.

Answer 3

Result: Negative. Sucrose is non-reducing in Benedict's Reagents. Therefore, no colored precipitate is formed.

Answer 4

Benedict's reagent test for simple sugars. Some example of simple sugars include glucose and fructose. Sucrose and lactose can not be identified using Benedict's reagent.