(a) Define olfactory indicators. Name two subtances which can be used as olfactory indicator.
(b) Choose strong acids from the following:
CH3COOH, H2SO4, H2CO3, HNO3
Science
Class 10
3239
Michael
Answer.
(a) Those substances whose smell (odour) changes in acidic or basic solution are called olfactory indicators, e.g. onion and vanilla.
(b) H2SO4 and HNO3 are strong acids.
Olfactory indicators are those indicators that help to identify whether the given solution is acidic or basic by changing their smell instead of colour as other indicators do.
For example onion, vanilla, clove, etc
Onion: Paste or juice of onion loses its smell when added with base. It does not change its smell with acid.
Vanilla: The smell of vanilla vanishes with base, but it’s smell does not vanishes with an acid.