Question

Nature of methyl orange is:
A. acidic
B. basic
C. neutral
D. none of these

Answer 1

Hint:We should understand that to determine the nature of methyl orange we will understand the concept of pH. The pH value is known to determine the potential of hydrogen. It is a scale used to specify the acidity or basicity of an aqueous solution. The range goes from \[0{\text{ }} - {\text{ }}14\], with $7$ being the neutral point.

Complete step by step answer:
We know that methyl orange is a pH indicator and it is frequently used in titration due to its clear and distinct colour variance at different pH values.
Also, we should know that methyl orange shows red colour when it is in acidic medium and yellow colour in a basic medium. As the property of ethyl orange is that it changes its colour at $p{K_a}$ of a mid-strength acid, it is usually used in titration of acids.
We know that methyl orange is a weak acid which dissociates in water forming orange neutral molecules. Under acidic conditions, the equilibrium is to the left and the concentration of the neutral molecules is too low that the orange colour is not visible.
It is red in pH under $3.1$, yellow in pH $4.4$, and orange in between with a $p{K_a}$ of $5.1$. From this, we get to know that methyl orange is a weak acid which gets dissociated in water forming orange neutral molecules. Therefore, we can conclude that the nature of methyl orange is basic.
Hence, the correct answer is option B.

Note:
Murexide and methyl red both can be considered as promising enhancers of sono-chemical destruction of chlorinated hydrocarbon pollutants. Thus, the yellow formed in the reaction is the co-base of the red form. Also, we should note that methyl orange has the property to change its colour in alkaline and neutral water yellow colour. If in case the water becomes more acidic then it turns red immediately. Thus, the point of colour change is at pH equal to $4.3$.