Question

Which of the following is more acidic in nature?
A.HClO
B.$HCl{O_2}$
C.$HCl{O_3}$
D.$HCl{O_4}$

Answer 1

Hint: Oxyacid is an acid that contains oxygen. Specifically it is a compound that contains hydrogen, oxygen and at least one other element. Acidity of the oxyacids increases with the increase in oxidation number.

Complete step by step answer:
Oxidation number or oxidation state is the total number of electrons that an atom either gains or losses in order to form a chemical bond with another atom.
Therefore,
Oxidation number of Cl in HClO is +1 , $HCl{O_2}$ is +3 , $HCl{O_3}$ is +5 and $HCl{O_4}$ is +7.
 We know that the acidity of oxyacids of halogen increases with increase in oxidation number of halogen.
Therefore,
$HCl{O_4}$ Is most acidic among the given choices.

Hence, option D is correct.

Additional information:
Perchloric acid i.e. $HCl{O_4}$ is an extremely powerful oxidant. Owing to its strong oxidizing properties, this compound exhibits very high reactivities towards most metals. Furthermore, it is also reactive towards organic matter and is also corrosive to the skin. Therefore, adequate safety measures must be taken while handling this compound. It is a colorless aqueous solution which is stronger than nitric acid and sulfuric acid. It is also used to prepare ammonium perchlorate which is an important component of rocket fuels.

Note:
The strength of an oxyacid is defined by the extent to which it dissociates in water (i.e. its ability to form ${H^ + }$ ions). In general, the relative strength of oxyacids can be predicted on the basis of the electronegativity and oxidation number of the central metal atom.