Question

Dried coconut Gives purple colour

when two drops of

copper sulphate

solution and 10

drops of caustic

soda is added to it.​

Answer 1

Answer:

When two drops of copper sulphate and ten drops of caustic soda or NaOH is added to the egg, it turns violet. This indicates the presence of proteins.

This is Biuret's test and the principle is simple as follows:

In the presence of an alkaline medium (caustic soda or NaOH), the Cu^2+

ions get reduced to Cu+ and bind to the egg proteins, thereby giving a violet colour.