Determination of sulphate with standard lead nitrate solution

26 DETERMINATION OF SULPHATE WITH STANDARD LEAD NITRATE SOLUTION 

Solutions as dilute as 0.001 M with respect to sulphate may be titrated with 0.01 M lead nitrate solution in a medium containing 30 per cent ethanol with reasonable accuracy. For solutions 0.01 M or higher in sulphate the best results are obtained in a medium containing about 20 per cent ethanol. The object of the alcohol is to reduce the solubility of the lead sulphate and thus minimise the magnitude of the rounded portion of the titration curve in the vicinity of the equivalence point. The titration is performed in the absence of oxygen at a 

Reagents. Potassium sulphate. Prepare an approximately 0.01 M solution in a lOOmL graduated flask using an accurately weighed quantity of the solid. 

Lead nitrate solution, approx. 0.1 M. Prepare similarly in a lOOmL graduated flask from a known weight of the dry solid. 

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