When Fehling's solution is added to an aldehyde it turns brick red
I think you are referring to the test using Fehlings solution. Fehlings solution oxidises aldehydes and ketones and formic acid and is in turn reduced. The red precipitate is the copper(I) oxide formed by reduction of the copper(II) complex found in Fehlings solution. Acetic acid is not readily oxidised and so there is no precipitate. See link for more information on what the complex is in Fehlings solution and how it is prepared.
Fehling's A solution is blue in color due to the presence of copper sulfate.
Fehling's solution is originally blue in color due to the presence of copper ions.
Fehling's solution is typically blue in color due to the presence of copper ions. When Fehling's solution is mixed with reducing sugars, such as glucose, it turns from blue to brick-red or yellow-brown due to the formation of a copper oxide precipitate.
Blue in Base
I think you are referring to the test using Fehlings solution. Fehlings solution oxidises aldehydes and ketones and formic acid and is in turn reduced. The red precipitate is the copper(I) oxide formed by reduction of the copper(II) complex found in Fehlings solution. Acetic acid is not readily oxidised and so there is no precipitate. See link for more information on what the complex is in Fehlings solution and how it is prepared.
Fehling's A solution is blue in color due to the presence of copper sulfate.
Fehling's solution is originally blue in color due to the presence of copper ions.
Acids turn universal indicator solution red.
Fehling's solution is typically blue in color due to the presence of copper ions. When Fehling's solution is mixed with reducing sugars, such as glucose, it turns from blue to brick-red or yellow-brown due to the formation of a copper oxide precipitate.
Red litmus paper would turn blue in a phosphate solution, indicating that the solution is basic.
Yes, Ribose will turn Benedict's solution red because it is a reducing sugar. Benedict's solution changes color when it reacts with reducing sugars like ribose due to the formation of a red-orange precipitate of copper(I) oxide.
The Fehling A solution contain copper sulfate.The Fehling B solution contain sodium potassium tartrate and sodium hydroxide.
A positive result for the Fehling's test indicates the presence of a reducing sugar such as glucose or fructose in the solution. This is shown by the formation of a brick-red precipitate when the Fehling's reagent is added and heated with the sugar solution.
A strip of litmus paper will turn red in an acidic solution.
Cu2O gives red ppt when heated with fehlings soln
lime juice and soap solutions turn red in turmeric because turmeric is an organic indicator which turns red in acidic or basic solution and lime juice is an acidic solution while soap is a basic solution