Wheo the reaction: ${\mathrm{Cl}}^{-}+{\mathrm{ClO}}_3^{-}⟶{\mathrm{Cl}}_2+{\mathrm{H}}_2\mathrm{O}$ is balanced in acid solution what is the ratio of ${\mathrm{Cl}}^{-}$ to ${\mathrm{ClO}}_3^{-}?$

When the reaction is balanced with smallest whole number then it can be given as,

$5{\mathrm{Cl}}^{-}+{\mathrm{ClO}}_3^{-}+6{\mathrm{H}}^{+}⟶3{\mathrm{Cl}}_2+3{\mathrm{H}}_2\mathrm{O}$

Here, ratio of coefficient of ${\mathrm{Cl}}^{-}$ ion to ${\mathrm{ClO}}_3^{-}$ is $\frac{5}{1}$.