• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

To find out the Ka of ethanoic acid, chloroethanoic acid and dichloroethanoic acid.

Extracts from this document...


Experiment 17 21-4-99 Aim: To find out the Ka of ethanoic acid, chloroethanoic acid and dichloroethanoic acid. Procedure: 1. The pH meter is calibrated, using a buffer solution of accurately known pH. 2. 20.0cm3 of 0.10M ethanoic acid was pipetted into a conical flask. 3. 0.10M sodium hydroxide solution was titrated using phenolphthalein as indicator, until the solution was just turned pink. 4. A further 20.0cm3 of the same ethanoic acid solution was added to the flask and was mixed thoroughly. 5. The pH of the resulting solution was determined. Result: Volume of NaOH used is recorded below: Trial (cm3) 1st time (cm3) ...read more.


1 [H+] ? Ka 3. [H+] ? Ka -log Ka = -log [H+] pKa = pH 4. The aim of neutralization is to neutralize all the acid, and make the concentration of the salt same as the concentration of the 20.0cm3 acid. Therefore the titre need not be exactly 20.0cm3. 5. If the titre were, say 22.0cm3, a further 20.0cm3 of acid is still added. The mole of the salt from neutralization is same as the mole of 20.0cm3 acid. As equal mole of salt and acid is needed, a further 20.0cm3 of acid is still added. 6. For CH3COOH, pKa = pH pKa = 4.6 Ka = 2.514 ? ...read more.


9. This method can also be used to determine the dissociation constant of weak bases. For ammonia: Kb = [OH-] ? Kb Procedure 1~5 can be repeated while the acid is replaced by NH3 and NaOH is replaced by HCl. For the pH is known, by 14 - pH = pKb the Kb can be found out. Conclusion: Ka ethanoic acid 2.514 ? 10-5 chloroethanoic acid 0.001 dichloroethanoic acid 6.310 ? 10-3 Discussion: 1. Distilled water can be added to buffer solution. But Distilled water can not be added to the conical flask because it will alter the pH of the solution 2. The pH meter should be calibrated by washing it with deionized water and then with the acid. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Aqueous Chemistry section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Aqueous Chemistry essays

  1. Analysing the ethanoic acid concentration in different types of vinegars.

    I will now repeat this for each of my other vinegars following the same steps. Cider Vinegar: Titration no. 1 2 3 Start position 18.9 28.2 37.5 Final position 28.2 37.5 46.8 NaOH used 9.3 9.3 9.3 Average NaOH used = (9.3 + 9.3 + 9.3)/3 = 9.3 Acid Concentration = 0.93 mol/dm3 White wine vinegar: Titration No.

  2. Obtain pure samples of Ethanol (CH3CH2OH) and Ethanoic Acid (CH3COOH) from fermented Yeast (Saccharomyces ...

    If breakage does occur seek teachers help. PRACTICAL 1- PREPARATION OF ETHANOL USING YEAST TO CARRY OUT A FERMENTAION IN A BIOREACTOR This practical was carried out as a class demonstration. A traditional bioreactor was set up in which there was solution which was being fermented.

  1. Indigestion - find out the composition of tablets which are for indigestion and compare ...

    In addition Bisodol indigestion relief tablets contain saccharin, maize starch, sucrose, calcium stearate and peppermint oil flavouring. 30 tablets Price: �1.95Including VAT at 17.5% Rennie Peppermint Calcium carbonate Ph Eur 680mg and heavy magnesium carbonate Ph. Eur 80mg. Each tablet also contains: Sucrose, glucose (250mg), peppermint flavour, talc, providone, saccharin sodium, magnesium stearate.

  2. Investigate the factors affecting Ka of a weak acid.

    So if an increase in carbon chain length can decrease [H+], then at the same time it can increase [HA]. If [HA] increases, Ka decreases (Ka tells us the acidity). pKa increases (since it is in a negative logarithm relationship).

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work