9. COORDINATION COMPOUNDS
1. Choose the most correct option.
i. The oxidation state of cobalt ion in the complex [Co(NH3)5Br]SO4 is
a. +2
b. +3
c. +1
d. +4
Answer:-
+3
Explanation:
It is known that the sulfate ion carries a charge of -2, represented as \[\ce{SO^{2-}_4}\]
Now, consider the complex ion [Co(NH3)5Br]2+
The oxidation state of NH3 is 0
The oxidation state of Br is -1
Let the oxidation state of the Cobalt ion be represented as x
So, x + (3 × 0) × 5 + (-1) = +2
⇒ x – 1 = +2
⇒ x = +3
Therefore, the oxidation state of the cobalt ion is +3.