HVZ reaction of acetic acid leads to the formation of

Hell Volhard Zelinsky (HVZ) reaction: The aliphatic Carboxylic acids containing α-hydrogen atom reacts with Cl₂ or Br₂ in presence of red phosphorus to give α-haloacids.

CH₃COOH $\stackrel{{\mathrm{Cl}}_2,\mathrm{p}}{\to }$CH₂ClCOOH $\stackrel{{\mathrm{Cl}}_2,\mathrm{p}}{\to }$ Cl₂CHCOOH $\stackrel{{\mathrm{Cl}}_2,\mathrm{p}}{\to }$Cl₃CCOOH

Acetic acid           Monochloro                 Dichloro          Trichloroacetic  acid                                                 acetic acid           acetic acid