Question

Olfactory indicator help in identify whether the given solution is acidic or basic by changing:
A. colour
B. Smell
C. Texture
D. All of the above

Answer 1

Hint: These are the indicators which are used in laboratories to check whether a given solution is a basic in nature or acidic in nature. Onion,clove oil and vanilla extract are the two Olfactory indicators which are commonly used in laboratories. This indicator result is detected by one of the sense organs that is the nose.

Complete step by step answer:
Olfactory is derived from the Latin word "olfacere" which means to smell. Olfactory indicators are the indicators which are used in the laboratories to detect whether the solution is acidic or alkaline by help of the sense of smell.Indicators include onion,clove oil,vanilla extract are commonly used.
The characteristic smell of vanilla extract vanishes when a basic solution is added while in acidic solution there is no alteration in the smell of vanilla extract takes place. Thus it helps to identify the unknown basic solution in the laboratory. Similarly clove oil and onion are also used for identifying the basic solution.
The correct option is B i.e. smell.

Additional information: Some pH indicators are also available that are also beneficial for the identification of the solution whether it is acidic or basic. These pH indicators change colour when they react with the solution and give a characteristic colour that resembles the particular solution. This indicator result is detected visually.

Note:
The alkali and acid are classified on the basis of the concentration of hydrogen ion or hydronium ion present in the solution. If the concentration of hydrogen ion is more then the solution is acidic and the pH goes downward ranging from 1 to 7 and if the solution is having more hydronium ion concentration then the solution is basic and the pH moves upward ranging from 7 to 14. If the pH is 7 then the solution is considered to be a neutral solution.
Examples of naturally occurring acids are lemon,vinegar,orange,tomato while natural occurring bases are washing soda(sodium carbonate),baking soda(sodium bicarbonate).