${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}\stackrel{\mathrm{PCC}}{\to } \mathrm{X} ; {\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{OH}\stackrel{{\mathrm{CrO}}_3+{\mathrm{H}}_2{\mathrm{SO}}_4}{\to } \mathrm{Y} ;$ X and Y respectively are

PCC is useful in controlled oxidation. Primary alcohols give aldehydes;

$\mathrm{X} \mathrm{is} {\mathrm{CH}}_3-\mathrm{CHO};$

${\mathrm{CrO}}_3+{\mathrm{H}}_2{\mathrm{SO}}_4$ is Jone's reagent. It oxidizes primary alcohols to carboxylic acids;

$\mathrm{Y} \mathrm{is} {\mathrm{CH}}_3-\mathrm{COOH} ;$