Special Procedure For Limit Test Of Chloride and Sulphate For Sodium Bicarbonate

Aim: To perform a special in limit test of sulphate and chloride in sodium

Principle:

In this special procedure the acid added to neutralize the alkaline carbonate and then the sulphate ion reacts with barium sulphate reagent.

Reaction:

                 CO3-   + 2HCl  --------->  H2O + CO2 + H+ 

Procedure:

Suspend 1g of sample in 10 ml of distilled water, neutralize with HCl and dilute to 15 ml with distlilled water

Standard Color	Sample color
Pipette out 1ml of 0.1089% w/v of standard potassium sulphate solution in a clean Nessler's cylinder and dilute to 25ml with distilled water add 2ml of dilute HCl and 5ml of Barium sulphate reagent. Make up the volume up to 50 ml by adding distilled water. Allow to stand for 5min.	Take above solution in a clean Nessler's cylinder. Add 2ml of dilute  HCl and 5ml of Barium Sulphate reagent. Make up the Volume up to 50 ml by adding distilled water. Allow to stand for 5min.

Comparison:

Compare the sample turbidity with standard turbidity by viewing the Nessler's cylinder against white back ground.

For Chloride

1.25g in dissolve in 15 ml of water add 2ml of nitric acid

Standard Color	Sample color
Pipette out 1ml of 0.05845% w/v of Standard NaCL solution in a clean Nessler's Cylinder. Add 10 ml of dilute Nitric acid and make up the volume up to 50 ml by adding distilled water. Add 1 ml of 0.1M silver nitrate and allow to stand for 5min.	Above solution is taken in a clean Nessler's cylinder. Add of dilute Nitric acid . Add 1ml of 0.1M silver nitrate and allow to stand for 5 min.

Comparison

Compare the sample turbidity with standard turbidity by viewing the Nessler's cylinder against white background.

Report:

1. When viewed transversely against a dark background, the turbidity produced in the sample( KMnO4) is less/more than the standard turbidity. Hence the given sample passes/ fails the limit test for chloride.
2. When viewed transversely against a dark background, the turbidity produced in the sample (KMnO4) is less/more than the standard turbidity. Hence the given sample passes/ fails the limit test for Sulphate.