# How do you write a balanced equation for this redox reaction using the smallest whole number coefficients?

## The reaction occurs in aqueous acidic solution. ${\text{ClO"^(-)+"I"_2->"Cl"^(-)+"IO}}_{3}^{-}$

Sep 27, 2017

Well try.....

${I}_{2} + 5 C l {O}^{-} + {H}_{2} O \rightarrow 2 I {O}_{3}^{-} + 5 C {l}^{-} + 2 {H}^{+}$

#### Explanation:

Hypochlorite is REDUCED.....$\stackrel{+ I}{C} l \rightarrow \stackrel{- I}{C} l$

$C l {O}^{-} + 2 {H}^{+} + 2 {e}^{-} \rightarrow C {l}^{-} + {H}_{2} O$ $\left(i\right)$

Charge and mass are balanced, so tick.....

And elemental iodine is oxidized.....${\stackrel{0}{I}}_{2} \rightarrow \stackrel{+ V}{I}$

$\frac{1}{2} {I}_{2} + 3 {H}_{2} O \rightarrow I {O}_{3}^{-} + 6 {H}^{+} + 5 {e}^{-}$ $\left(i i\right)$

Charge and mass are balanced, so double tick.....

And so we take $5 \times \left(i\right) + 2 \times \left(i i\right)$.........

${I}_{2} + 5 C l {O}^{-} + {H}_{2} O \rightarrow 2 I {O}_{3}^{-} + 5 C {l}^{-} + 2 {H}^{+}$

Is this balanced with respect to mass and charge? If it is not, then we may reject it out of hand!