1cm3 (roughly) of pure ethanoic acid Full range indicator
A test tube A pipette full of water 5cm3 of sodium carbonate (Na2CO3).
1. Put 1cm3 of ethanoic acid into a test-tube
2. Add
water and note if they mix various proportions:
3. Add
few drops of indicator. Colour:
4. Add
sodium carbonate solution. Observation:
What type of intermolecular force helps water and ethanoic acid to mix?
Is ethanoic acid strong enough to displace carbon dioxide from carbonates?
Na2CO3(aq) + 2CH3COOH(l)
2Na+ + 2CH3COO- + H2O +
CO2
Ka for ethanoic acid = 1.7 which is big compared to other carboxylic acids, so ethanoic acid is more dissociated and thus a strong acid.
10cm3 0.1M ethanoic acid beaker Full range indicator (or pH meter)
25cm3 0.1M NaOH Pipette or syringe
1. Put 10cm3 of ethanoic acid into beaker
2. Add few drops of indicator
3. Stir and add 3cm3 of NaOH
4. Note the pH
5. Repeat last 2 for 5 times
No. of the go |
Measure of the pH / Colour of the indicator |
1 |
|
2 |
|
3 |
|
4 |
|
Final pH |
Neutralisation reaction CH3COOH(aq) + NaOH (aq) Na+(aq) + CH3COO-(aq) + H2O(l)
1 cm3 of ethanoic acid 2cm3 of ethanol 3 drops of conc. H2SO4 A test-tube
Water bath with HOT WATER Small beaker Na2CO3
1. Smell ethanol and ethanoic acid
2. Add ethanol to ethanoic acid
3. Add CAREFULLY H2SO4
4. Warm the mixture GENTLY for 5 min.
5. Smell the mixture. It is like / not like the starting material.
6. Put the mixture into a beaker filled with Na2CO3
7. Stir and Smell
8. Smell ethyl ethanoate from a bottle. It smells / smells not like my mixture.
9. If some esters are available, smell them cautiously
Name of compound |
What I see |
What I smell |
10. If required look up the table of other esters from a book p.325 and make them in a same way.