Ethanol oxidized to produce Ethanoic acid.

Which of the following reagent is used for the reaction?

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}\stackrel{?}{\to }{\mathrm{CH}}_3\mathrm{COOH}$

${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}\underset{2\left[\mathrm{O}\right]}{\overset{{\mathrm{K}}_2{\mathrm{Cr}}_2\mathrm{O}7/\mathrm{H}+}{\to }}{\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{COOH}+{\mathrm{H}}_2\mathrm{O}$

With either acidified ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ or alkaline ${\mathrm{KMnO}}_4$, ethanol is converted to ethanoic acid.
The orange colour of ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ turns green throughout this reaction. As a result, this response can be used to identify alcohol.