How to prepare and Standardize 0.2 N Hydrochloric Acid Volumetric Solution.

How to prepare and Standardize 0.2 N Hydrochloric Acid Volumetric Solution.

Preparation of 0.2 N Hydrochloric acid volumetric solution.

➤ Glass ware and instruments required.

Beaker, Glass stirrer, Graduated Pipettes, Graduated cylinder, Analytical balance, Sucker, Volumetric flask, Fume hood.

 ➤ Reagents required.

Hydrochloric acid.
Molecular wt HCl, 36.46
Sodium carbonate primary standard. (Previously dried for 1 hour at 270°C - 300°C)
Methyl red indicator.

 ➤ Preparation.

Transfer 16 ml of hydrochloric acid reagent grade to 1000 ml volumetric flask containing 100 ml water, dilute up to the mark with same solvent.  

➤ Standardisation.

Accurately weigh about 0.3 g sodium carbonate PS, previously dried for 1 hour at 270°C - 300°C, in 250 ml conical flask. Dissolve in 100 ml water. Add 2 drops of methyl red indicator solution. Titrate with 0.2 N / 0.2 M hydrochloric acid till the solution becomes faint pink. Heat the solution to boiling, cool to room temperature by holding the flask under tap water. Continue titration to faint pink colour. Repeat the steps of heating and cooling till faint pink colour is restored. 

➤ Calculations.

                                 g  Na₂CO₃  x  0.2

N / M= --------------------------------------------------

                      0.010598  x   Burette reading in ml