Question

The atomicity of one of the acids below is one?
(A) $ {H_2}S{O_4} $
(B) $ {H_2}C{O_3} $
(C) $ {H_2}{C_2}{O_4} $
(D) $ C{H_3}COOH $

Answer 1

Hint: Atomicity is defined as the total number of atoms present in a molecule. For example, each molecule of oxygen is composed of two oxygen atoms. So atomicity of oxygen is two In older contexts, the term atomicity is sometimes used in the same sense as valency.

Complete answer:
Atomicity means the state of being made up of atoms or the number of atoms in the molecules of an element. Or a less common name for valency.
On the basis of atomicity, molecules can be classified as:
-Monatomic – composed of one atom
-Diatomic – composed of two atoms
-Triatomic – composed of three atoms
-Polyatomic – composed of three or more atoms
Atomicity is determined by adding the number of atoms present in a molecule. The sum of the mass of each element of the compound will give the molecular mass. Atomicity represents the total number of atoms present in a molecule.
 $ {H_2}S{O_4}(aq) + 2NaOH(aq) \to 2{H_2}O + N{a_2}S{O_4}(aq) $
 $ {H_2}C{O_3}(aq) + 2NaOH(aq) \rightleftharpoons 2{H_2}O(l) + N{a_2}C{O_3}(aq) $
 $ {H_2}{C_2}{O_4}(aq) + 2NaOH(aq) \rightleftharpoons N{a_2}{C_2}{O_4} + (aq) + 2{H_2}O $
Again the formation of oxalate ions is disfavored.
 $ {H_2}C - C{O_2}H + NaOH(aq) \rightleftharpoons {H_3}C - C{O_2}^ - N{a^ + } + {H_2}O $
We need to find the only monoprotic acid. Acetic acid is the only monoprotic acid, and requires the one equivalent base for equivalence.
So, the correct answer is (D) $ C{H_3}COOH $ .

Note:
All metals and some other elements, such as carbon, do not have a simple structure but consist of a very large and indefinite number of atoms bonded together. Their atomicity cannot be determined and is usually considered as one. Atomicity may vary in different allotropes of the same element.