Analytical test of Oxalic acid or Polyprotic acid
(a) The aqueous solution turns blue litmus red.
(b) The aqueous solution includes effervescences along with NaHCO3.
(c) The neutral solution provides a white precipitate with calcium chloride solution. Oxalic acid is insoluble in acetic acid.
(d) It decolourises hot potassium permanganate solution comprising dilute sulphuric acid.
(d) Along with hot conc. H2SO4, it evolves carbon monoxide that burns with blue flame.