c3h3co2h

from The Collaborative International Dictionary of English v.0.48
Tetrolic \Tet*rol"ic\, a. (Chem.)
   Of, pertaining to, or designating, an acid, {C3H3.CO2H}, of
   the acetylene series, homologous with propiolic acid,
   obtained as a white crystalline substance.
   [1913 Webster]
    

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