Preparation and standardization of 1.0 M Hydrochloric acid

1.0 OBJECTIVE 

Preparation and standardization of 1.0 M Hydrochloric acid 

2.0 SCOPE

This SOP is applicable to Preparation and standardization of 1.0 M Hydrochloric acid  in company.

3.0 BACKGROUND 

NIL

4.0 RESPONSIBILITY

4.1 QC-Chemist 

4.2 Head-QC

5.0 PROCEDURE

5.1 Reagents : Hydrochloirc acid, Sodium carbonate, methyl red and water.

5.2 Glassware: Volumetric Flask, measuring cylinder, Burette, Conical Flask, beaker and Pipettes. 

5.2 Preparation of Solution:

Dilute 85 ml of hydrochloric acid(37%) with water to produce 1000 ml

5.4 Principle:

The Standard solution of sodium carbonate is used to determine the exact concentration of a hydrochloric acid solution. The neutralization reaction that occurs is as follows:

In the first reaction sodium carbonate reacts with hydrochloric acid and forms sodium bicarbonoate and sodium chloride.

In the final reaction, sodium bicarbonoate reacts with hydrochloric acid and forms Sodium chloride, Water and carbon dixode.

The total reaction Equation is as follows 

One mole of sodium carbonate and two moles of hydrochloric acid reacts and forms one mole of sodium chloride, water and carbon doxide. when neutralization occurs at the end point the solution becomes faint pink.

5.5 Standardization:

Weigh accurately about 1.500g of anhydrous sodium carbonate, previously heated at about 270⁰C for 1 hour. Dissolve it in 100ml of water and add 0.1ml of methyl red solution. Add the acid slowly from a burette, with constant stirring, until the solution becomes faintly pink. Heat the solution to boiling, cool and continue the titration. Heat again to boiling and titrate further as necessary until the faint pink colour is no longer affected by continued boiling.

1 ml of 1 M hydrochloric acid is equivalent to 0.05299 g of Na2CO3

Calculation:

5.3 Calculation

MF = W x actual molarity of Hcl / V x 0.05299 (factor) 

Where

V = Volume of hydrochloric acid consumed in ml.

W = Weight of sodium carbonate in g.

Example:

V=26.5 ml

W=1.5032gm

 = 1.5032x1

  26.5 x 0.05299 

 =1.07047 M

 Note :

•Re-standardize before use.

•Store in amber bottle with well fitted suitable stoppers which prevents access to atmospheric carbon dioxide.

•Discard the solution after 30 days.

•For storage and labeling follow the general procedure.