which of the folowing is an olfactory indicator?
1 onion
2 vanilla essence
3 clove oil
Onion and Vanilla extract are the olfactory agent as they do not give their characteristic smell in basic solution but retain their odor in acidic solution.
Vanilla, clove and onion are ___ indicators.
Vanilla, clove and onion are __ indicators.
How can vannila essence and clove oil be used as indicators