Question

What is the oxidation number of gold in the complex ${[AuCl_4]^{1-}}$ ?

• A. 4
• B. 3
• C. 2
• D. 1

Answer 1

Answer: (B)

3

Answer 2

Let $x$ be the oxidation number of gold $(Au)$ in the complex $\left[ AuCl _{4}\right]^{-1}$
$\therefore x+4(-1)=-1$
$\Rightarrow x=-1+4$
$\Rightarrow x=+3$

Hence, the oxidation number of gold is +3