Question

Which of the following arrangements represent increasing oxidation number of the central atom?

Options

• \[\ce{CrO^{-}2, ClO^{-}3, CrO^{2-}4, MnO^{-}4}\]

• \[\ce{ClO^{-}3, CrO^{2-}4, MnO^{-}4, CrO^{-}2}\]

• \[\ce{CrO^{-}2, ClO^{-}3, MnO^{-}4, CrO^{2-}4}\]

• \[\ce{CrO^{2-}4, MnO^{-}4, CrO^{-}2, ClO^{-}3}\]

Answer 1

\[\ce{CrO^{-}2, ClO^{-}3, CrO^{2-}4, MnO^{-}4}\]

Explanation:

Let the oxidation number of central atom be 'y'.

Oxidation number of \[\ce{O}\] = −2

\[\ce{CrO^{-}2}\]: y + 2 × (−2) = −1

y − 4 = −1 or y = +3

\[\ce{CrO^{2-}4}\]: y + 4 × (−2) = −2

y − 8 = −2 or y = +6

\[\ce{ClO^{-}3}\]: y + 3 × (−2) = −1

y − 6 = −1 or y = +5

\[\ce{MnO^{-}4}\]: y + 4 × (−2) = −1

y − 8 = −1 or y = +7

Increasing order of oxidation number of the central atom is:

\[\ce{CrO^{-}2 < ClO^{-}3 < CrO^{2-}4 < MNO^{-}4}\]