A primary alcohol can be oxidized to an aldehyde by choosing the reagent

The reagent ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NH}}^{+}{\mathrm{CrO}}_3{\mathrm{Cl}}^{-}$oxidizes alcohol to aldehydic stage. 

A primary alcohol can be oxidized to an aldehyde by choosing the reagent ${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{NH}}^{+}{\mathrm{CrO}}_3{\mathrm{Cl}}^{-}$.