carboxylic acids and derivatives

What does an ester and water make?

In acidic conditions

Carboxylic acid and alcohol

Mix 10 cm3 of propan-2-ol with 10 cm3 of ethanoic acid.

Add 5 drops of concentrated sulfuric acid.

Reflux this reaction mixture for 20 minutes

Describe how this step should be done.

I

• explain any safety precautions needed other than eye protection

Use a fume cupboard And avoid breathing toxic compounds

Wear gloves as compounds are corrosive

Use a water bath as compounds are flammable

Hazards of concentrated sulfuric acid and ethanoic

Flammable

Corrosive

Toxic

Draw and label a diagram below to show how the impure solid is filtered

What does an ethanoic acid and sodium hydroxide form?

Ethanoate ion and sodium ion —sodium ethanoate ion

So basically an ester but both those things are charged and still on one structural formula together

What is formed in the reaction of ethanoic acid and sodium carbonate?

Sodium ethanoate ion and water and carbon dioxide

Draw ethyl 2-methylpropanoate

Propyl methanoate and water

Alkaline conditions

Sodium ethanoate ion and ethanol

Methyl 3-methyl butanoate and water forms what

React 2 methyl propanal with KCN and HCl

What type of reaction is esterificaiton?

Reversible reaction

So remember to add the arrow

What is the purpose of sodium carbonate in the aspirin experiment?

To react with excess acid

What precaution should be taken and why before shaking the separating funnel

Add a stopper

To prevent spillages

Suggest how the purity of the ester can be confirmed during distillation?

Compare its boiling point to a data book value

State why ethanoic anhydride is preferred to ethanoyl chloride for this preparation

Less corrosive

Give the name of the mechanism for the reaction of

2-hydroxybenzenecarboxylic acid with ethanoic anhydride

Nucleophilic addition elimination

Suggest why reflux is not essential when the flask is heated to 85C for 10 minutes

Boiling points are above 85

Suggest the identity of 2 impurities present in the filtered solid aspirin before it is washed

1-ethanoic acid

2-phosphoric acid

State the physical property that is measured to check the purity of the

aspirin.

Describe two ways the result would show that the product is impure

Lower than data book value

Melts over a range of temperatures

What is the mechanism involved in hydrolysis

Nucleophilic addition elimination

Name 2 pollutants released from the complete combustion of biofuel

Sulfur dioxide-acid rain

Carbon dioxide

Catalyst for aspirin experiment

Phosphoric acid or sulfuric acid

Draw a diagram for reflux apparatus

Name this

N,N-dimethyl ethanamide

Identify 2 mistakes and explain

Bung- pressure build up

Water goes the wrong way through a condenser

Why is there a build up of pressure in the separating funnel after adding sodium carbonate to the distillate-aspirin practical

Carbon dioxide is produced

Give a reason why 2 layers form in the separating funnel

Insoluble in water

A mixture of ethanol, ethanoic acid, and concentrated sulfuric acid,

with anti-bumping granules, is heated under reflux for 10 minutes.

2. The apparatus is rearranged for distillation.

3. The mixture is heated to collect the liquid that distils between 70 and

85 °C

4. The distillate is placed in a separating funnel. Aqueous sodium

carbonate is added, and a stopper is placed in the funnel. The

mixture is shaken, releasing pressure as necessary.

5. The lower aqueous layer is removed and the upper organic layer is

placed in a small conical flask.

6. Anhydrous calcium chloride is added to the sample in the conical

flask. The flask is shaken well and left for a few minutes.

7. The liquid from the flask is redistilled and the distillate is collected

between 74 and 79 °C

Suggest why ethyl ethanoate forms the top layer in a separating funnel aspirin practical

Less dense than water

Why is the percentage yield not 100%

Reversible reaction

Use for carboxylate ions

Soap

What reaction is addition elimination

Hydrolysis