How to Determine/Calculate the Strength of HCl
Rofiquzzaman Raju
Chittagong Textile Engineering College
Email: rtextile.finance@gmail.com
Introduction:
Textile industry is a chemical based industry. Different types of chemicals and auxiliaries used in textile wet processing. Among those Hydrochloric Acid (HCl) widely used in different process of dyeing. In the textile industry, Hydrochloric Acid (HCl) is used to neutralise alkaline residues in cotton in the cleaning process immediately prior to bleaching. Determination of chemical strength of HCl is important for textile industry. It he strength of HCl is not proper then the every process on textile is not proper. Titration is the best method for determination of strength of HCl. In this method 0.1 N NaOH is used for titration.
Objectives:
- To know about how determined the strength of HCl.
- To know about the titration process.
- To know about the solution making.
- To know about the end point of this testing.
Apparatus:
- Beaker
- Pipette
- Stirrer
- Graduate cylinder
- Electronic balance
- Burette
Reagents:
- HCl
- 0.1 N NaOH
- And Indicator (Phenolphthalein)
Determination of Strength of HCl:
4 ml HCl is taken
↓
Then it is diluted with 500 ml water
↓
From that solution 25 ml is taken
↓
After that 2-3 drops of indicator is added
↓
Then it is taken in Conical flask. Then this sample solution is treated with 0.1 N NaOH
End Point: The end point is determined when the permanent pink color solution stay.
Calculation:
Molecular equivalent weight of HCl = 36.5 gm
So, 1000 ml Molecular equivalent weight is 36.5
1 ml molecular equivalent weight is = 36.5/1000 = 0.0365 gm
In 500 ml water the amount of sample is 4 ml
So, 25 ml of water the amount of sample is = ( 4 X 25)/500 = 0.20
Normality of NaOH is 0.1 N
And volume used of KMnO4 is 24.5 & 25.6
Following formula used for determining strength of HCl:
Results and discussion:
| Required Amount of NaOH | Strength of HCl % |
| 24.5 & 24.6 | 44.712 & 44.895 |
| 23.7 & 22.3 | 43.252 & 40.697 |
| 24 & 23.2 | 43.8 & 42.34 |
| 23.8 & 24.1 | 43.435 & 43.982 |
| 23.7 & 23.5 | 43.252 & 42.887 |
From above results, we can say that the strength of HCl of different persons results have been obtained near to 43.5% and my results is 44.712 & 44.895. We have done experiment manually so something can be inaccurate measurement of pipette or burette reading. And at last, we can say that the strength of HCl is 44%.
Conclusion:
At last we can say that, how to determine the strength of HCl, is known by this experiment. Knowledge is gained from this experiment which is very helpful in our practical life.
You may also like: How to Determine the Strength of Hydrogen Peroxide (H2O2)
Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. Mr. Kiron is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.
