. Estimation of oxalic acid Aim : To estimate the amount of oxalic acid dissolved in ml of the given unknown solution volumetrically. For this you are given with a standard solution of HCl solution of normality . N and sodium hydroxide solution as link solution.
Principle: Neutralization of Sodium hydroxide by HCl is given below. To indicate the end point, phenolphthalein is used as an indicator. NaOH + HCl NaCl + H O → Neutralization of Sodium hydroxide by oxalic acid is given below. To indicate the end point, phenolphthalein is used as an indicator.
Oxalic acid Sodium oxalate 2NaOH + COOH COONa + 2H O → Short procedure: s.no Content Titration-I Titration-II Burette solution HCl (standard solution) Oxalic acid ( unknown solution) Pipette solution ml of NaOH link solution ml of NaOH link solution Temperature Lab temperature Lab temperature Indicator Phenolphthalein Phenolphthalein End point Disappearance of pink colour Disappearance of pink colour Equivalent weight of oxalic acid = Procedure : Titration–I (standard HCl )Vs ( link NaOH) Burette is washed with water, rinsed with HCl solution and filled with same HCl solution up to the zero mark. Exactly ml of NaOH is pipetted out into the clean, washed conical flask. To This solution to drops of phenolphthalein indicator is added and titrated against HCl solution from the burette. HCl is added drop wise till the pink colour disappears completely.
Burette reading is noted and the same procedure is repeated to get concordant values. organic organic - - - - Titration –I (standard HCl )Vs (link NaOH) s.no Volume of NaOH(ml) Burette readings Concordant value (Volume of std HCl) (ml) Initial (ml) Final (ml) Calculation : Volume of NaOH(link) solution V = ml Normality NaOH(link) solution N = ? N Volume of standard HCl solution V = ml Normality of standard HCl solution N = . N According to normality equation: V N x V x N .
N Normality NaOH (link) solution N = N