Question

some chemical reactants are listed in the table below. complete the table by filling in the oxidation state of the highlighted atom.

species	oxidation state of highlighted atom
oh⁻(aq)
i⁻(aq)
co₂(g)

Explanation:

Step1: Determine oxidation state of O

Oxygen usually has an oxidation - state of - 2 in compounds (except in peroxides). In $Cu_2O$, let the oxidation state of $Cu$ be $x$. The compound is neutral, so $2x+(-2)=0$.

Step2: Solve for $x$ in $Cu_2O$

$2x - 2=0$, then $2x=2$, and $x = + 1$.

Step3: Determine oxidation state of O in $OH^-$

Oxygen has an oxidation - state of - 2 in $OH^-$. Let the oxidation state of $H$ be $+1$. The overall charge of the ion is - 1. So, $(-2)+(+1)=-1$. The oxidation state of $O$ in $OH^-$ is - 2.

Step4: Determine oxidation state of I in $I^-$

The oxidation state of a monatomic ion is equal to its charge. So, the oxidation state of $I$ in $I^-$ is - 1.

Step5: Determine oxidation state of C in $CO_2$

Oxygen has an oxidation - state of - 2. Let the oxidation state of $C$ be $x$. For $CO_2$, $x + 2\times(-2)=0$. Solving for $x$ gives $x-4 = 0$, so $x=+4$.

Answer:

species	oxidation state of highlighted atom
$OH^-(aq)$	-2
$I^-(aq)$	-1
$CO_2(g)$	+4