Ask a Teacher

Search



HOW CAN WE PREPARE HYDROCHLORIC ACID?

Preparation of ~0.10M HCl
-------------------------------------------
 
1- Take a 1000 or 2000 ml of storage bottle. Wash it well with soap or detergent first. Rinse it out with tap and then with distilled water couple of times.
 
2 - Measure 1000 -ml of distilled water into a beaker. Heat the water to boiling.
 
3 - Then cool it to room temperature. Add about 8 ml of conc. HCl (12M), mix it well and store it in a stoppered bottle.

 Standardization of HCI
-----------------------------------------
1- Weigh duplicate ~0.20 to 0.25 g (± 0.1 mg) samples of previously dried standard Na2C03. Dissolve samples in ~100- ml distilled water; if it does not dissolve quickly, you may warm the solution.
 
2 - Cool the solution to room temperature and add ~3 drops of bromocresol green indicator, solution turns into blue. Titrate it with HCl until green color is reached.
 
3 - Heat and boil out C02 gently. You should obtain a blue color again at the end of this step. Cool to room temperature, and continue titration until yellow color is reached.
 
4 - Calculate the molarity of HCI, it should agree to about two parts per thousand. If they do not agree, repeat the procedure for the third time and take the avg. of the two closest results.
 


comments powered by Disqus