Question

The basicity of acetic acid is …….
A.${ 1 }$
B.${ 2 }$
C.${ 3 }$
D.${ 4 }$

Answer 1

Hint: The basicity of an acid is determined by the number of ionizable hydrogen atoms in the acid molecule. Basicity is measured on a scale called the pH scale.

Complete step-by-step answer:
-Acetic acid is a carboxylic acid. In this, a strong covalent bond is present between carbon and hydrogen. Here, the aqueous solution cannot provide sufficient energy for its dissociation.
-In acetic acid, ${ CH }_{ 3 }{ COOH }$, there is only one ionizable hydrogen, which is attached to oxygen.
${ CH }_{ 3 }{ COOH\rightleftharpoons CH }_{ 3 }{ COO }^{ - }{ +H }^{ + }$
As we see here that only one hydrogen ion releases so, it’s basicity is one although it has four hydrogen atoms.
Hence, the basicity of acetic acid is ${ 1 }$.
The correct option is A.

Additional Information:
-Factors affecting the basicity of acid are as follows:
-Electronegativity: The more electronegative the atom, the more it will donate the electrons, so it is less willing to share the electrons with the protons. Hence, it will be a weaker base.
-Size: When we compare the size of an atom in the same group of the periodic table, the larger the atom, the lower will be electron density and make it a weak base.
-Resonance: Delocalization of electrons occurs in resonance which causes a reduction in electron density. Due to this the basicity also decreases.

Note: The possibility to make a mistake is that in acetic acid there are four hydrogen present, so its basicity is ${ 4 }$ but the basicity of acetic acid is one, not four.