Question

Define indicators and olfactory indicators.

Answer 1

An Olfactory indicator is a substance whose smell varies depending on whether it is mixed into an acidic or basic solution. Olfactory indicators can be used in the laboratory to test whether a solution is a base or an acid, a process called olfactory titration. Onion and vanilla extract are examples.

Answer 2

Some substances whose odour  changes in acidic or basic medium