Halogenation at alpha position increases acid strength, so that the following acids are all stronger than acetic acid.
hɐlˌɑːdʒənˈeɪʃən æɾ ˈælfə pəzˈɪʃən ˈɪŋkɹiːsᵻz ˈæsɪd stɹˈɛŋθ, sˌoʊ ðætðə fˈɑːloʊɪŋ ˈæsɪdz ɑːɹ ˈɔːl stɹˈɔŋɡɚ ðɐn ɐsˈiːɾɪk ˈæsɪd.