Question

Biuret solution turns ______ detecting the presence of proteins in food.

• A. Pink colour
• B. Blue-black colour
• C. Violet colour
• D. Red colour

Answer 1

The correct option is C

Violet colour

Biuret solution is a blue liquid that changes to purple color when it reacts with proteins present in food. Biuret solution is made by mixing copper sulfate with sodium hydroxide. Copper sulfate gives a typical blue color to this solution, which is turned to purple after reacting with the proteins. This test is called as 'Biuret test'.