Molisch & Fehling Tests: Comparing Results

[spacetime]

Hey, what could be a compund that gives a positive Molisch test but a negative fehling's test?

 

[chem_tr]

Hello, I haven't remembered what is the Molisch test, but a negative Fehling's test indicates that the compound does not have any oxidizable group, especially the aldehyde one.

 

[ravenprp]

There are a few possible compounds that could give a positive Molisch test but a negative Fehling's test. One example is a non-reducing sugar such as sucrose. The Molisch test detects the presence of any carbohydrate, including non-reducing sugars, while the Fehling's test specifically detects reducing sugars. Another possibility is a compound that contains a ketone group, which would give a positive Molisch test but would not react with the copper ions in Fehling's solution. Additionally, certain aromatic compounds can give a positive Molisch test due to the presence of phenolic groups, but would not react with Fehling's solution. Ultimately, the results of these tests depend on the functional groups present in the compound being tested, so it is important to consider the specific properties of the compound in question.