Purity Test of Purified Water (For School & College level lab practical)

Purity Test of Purified Water

Requirement :

Test tube, test tube holder, test tube rack, labeling materials (pen, paper, scissors, gum). 

Reagent :

Litmus paper (red and blue),
BaCl₂,
AgNO₃,
Ammonium Oxalate,
NH₄OH,
Nessler's Reagent,
Sodium Sulfide,

Ingredients:

Supplied purified water. 

Procedure:

Experiment 1:

Some amount of purified water is taken in a test tube. 

Observation :

Clean, colorless, odorless.

Inference :

May be pure.

Experiment 2:

Litmus Test:
Some amount of purified water is taken in a clean test tube.

(a) A blue litmus paper is dipped into the solution.

(b) A red litmus paper is dipped into the solution. 

Observation :

(a) The colour of blue litmus paper is not changed.

(b) The colour of red litmus paper is not changed.

Inference :

(a) Absence of Acid.

(b) Absence of alkali.

Experiment 3:

Some amount of purified water is taken in a test tube. Few drops of BaCl₂ solution is poured into that test tube.

Observation :

No white precipitation is produced. 

Inference :

Absence of Sulphate (SO₄^2-) .

Experiment 4:

Some amount of purified water is taken in a test tube. Few drops of AgNO₃ solution is poured into it.

Observation :

No white precipitation is found.

Inference :

Absence of Chloride.

Experiment 5:

Some amount of purified water is taken in a test tube. Few drops of Ammonium Oxalate solution is poured into that test tube.

Observation :

No white precipitation is formed.

Inference :

Absence of Ca (Calcium).

Experiment 6:

Some amount of purified water is taken in a test tube. Few drops of NH₄OH solution is poured into that test tube.

Observation :

No white precipitation is formed.

Inference :

Absence of Mg (Magnesium).

Experiment 7:

Some amount of purified water is taken in a test tube. Few drops of Nessler's Reagent is added with that.

Observation :

No brown precipitation is formed.

Inference :

Absence of NH₃.

Experiment 8:

Some amount of purified water is taken in a test tube. Few drops of Sodium Sulfide solution is poured into that test tube.

Observation :

No brown, black or brownish black colour is produce.

Inference :

Absence of Pb (lead), Fe (Iron) and Cu (Copper).

Conclusion :

Supplied purified water is pure.

 

 

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