Question

The coordination number and the oxidation state of the element ‘E’ in the complex [E(NH₃)₄Cl₂]NO₃ are respectively.

Options

• 6 and 3

• 6 and 2

• 4 and 2

• 4 and 3

Answer 1

6 and 3

Explanation:

The coordination number is the number of donor atoms directly attached to the central metal atom E.

Here, there are 4 NH₃ ligands (neutral) and 2 Cl⁻ ligands (anionic) bound to E.

So, coordination number = 4 + 2 = 6

∴ Coordination number = 6

Let the oxidation state of E = x

x + 4(0) + 2(−1) = +1

x + 0 − 2 = +1

x − 2 = +1

x = +3

∴ Oxidation state = +3