Question

Olfactory indicator among the following is:
A. Clove
B. Turmeric
C. Soap
D. Rose petal

Answer 1

Hint : Olfactory indicators are indicators which help us to identify whether the solution is acidic or basic in nature by changing their smell rather than the colour. These indicators are used in laboratories to check whether a given solution is a basic or an acidic solution by a process known as olfactory titration.

Complete Step By Step Answer:
There are certain substances whose odour (smell) changes with PH value. In acidic solution their odour will be different and in basic solution their odour will be different. These substances are called olfactory indicators. The olfactory indicators have a characteristics odour. This odour in olfactory indicators is modified in acidic or basic solution and helps us in detecting whether a given sample solution is acidic or basic in nature.
These variety of indicators are used in laboratories to test the nature of a given solution, it could be a basic or an acidic solution by a process called olfactory titration. Onion, oil of cloves and vanilla are a number of the examples.
Clove oil is an olfactory indicator. In an acidic medium we will characteristics the smell of clove but it's inconceivable in base, to characteristics smell cannot be detected. Yes, clove oil is an olfactory indicator. In acid, its smell will be detected.
Turmeric, a standard spice in curry, as an indicator for acidity and basicity. The colour of Turmeric is yellow in acid and neutral substances, but changes its colour to bright red with bases. Learners can use their indicator to check household chemicals and determine which are basic.
Hibiscus, rose petals are olfactory indicators , which helps us to differentiate if a substance is acid or base supported by the smell produced. hibiscus flower extracts and rose petal extracts may be employed in the chemistry labs for testing acids and bases as both behave differently and alter color differently when tested against acid and bases .When added to acid, china rose flower changes its colour to bright pink and in some occasions even magenta. it'll change to green color when the identical extract is added to base.
Hence only soap isn't an Olfactory indicator.
Option (C) is correct.

Note :
An indicator could be a substance that changes its colourize acidic and basic medium. An indicator shows one modified acidic medium and different colorise basic medium so they're called indicators. indicators derived from natural sources are known as natural indicators. An indicator prepared from artificial substances is understood as a synthetic indicator.