Ncert Exercises & Solutions

Find out the oxidation number of chlorine in the following compounds and arrange them in increasing order of oxidation number of chlorine.

NaClO₄, NaClO₃, NaClO, KClO₂, Cl₂O₇, ClO₃, Cl₂O, NaCl, Cl₂, ClO₂.

Which oxidation state is not present in any of the above compounds?

Suppose that the oxidation number of chlorine in these compounds be x.

O . N . of Cl in {NaClO}_{4} ∴ + 1 + x + 4 (- 2) = 0 or, x = + 7

O . N . of Cl in {NaClO}_{3} ∴ + 1 + x + 3 (- 2) = 0 or, x = + 5

O . N . of Cl in NaClO ∴ + 1 + x + 1 (- 2) = 0 or, x = + 1

O . N . of Cl in {KClO}_{2} ∴ + 1 + x + 2 (- 2) = 0 or, x = + 3

O . N . of Cl in {Cl}_{2} O_{7} ∴ + 2 x + 7 (- 2) = 0 or, x = + 7

O . N . of Cl in {ClO}_{3} ∴ x + 3 (- 2) = 0 or, x = + 6

O . N . of Cl in {Cl}_{2} O ∴ 2 x + 1 (- 2) = 0 or, x = + 1

O . N . of Cl in NaCl ∴ + 1 + x = 0 or, x = - 1

O . N . of Cl in {Cl}_{2} ∴ 2 x = 0 or, x = 0

O . N . of Cl in {ClO}_{2} ∴ x + 2 (- 2) = 0 or, x = + 4

None of these compounds have an oxidation number of +2.

Increasing order of oxidation number of chlorine is : -1, 0, +1, +3, +4, +5, +6, +7

Therefore, the increasing order of oxidation number of Cl in compounds is

NaCl < Cl₂< NaClO < KClO₂ < ClO₂ < NaClO₃< ClO₃ < Cl₂O₇