A purple colour was obtained when sodium hydroxide solution and a drop of copper sulphate solution were added to a food substance. The food substance is lik...

A purple colour was obtained when sodium hydroxide solution and a drop of copper sulphate solution were added to a food substance. The food substance is likely to be a

Answer Details

The food substance is likely to be a protein. When sodium hydroxide solution and a drop of copper sulphate solution are added to a protein, it forms a violet or purple color. This is due to the formation of a complex between the copper ions and the peptide bonds in the protein molecules. The intensity of the color depends on the concentration of the protein in the solution.