3.9 Carboxylic acids

Question 1

define term hydrolysis

Answer 1

breaking a bond of water

Question 2

Name CH3CH2OOCCH2CH2CH3

Answer 2

ethylbutanoate

Question 3

construct equation when Methanoic Acid and Sodium Hydroxide react together

Answer 3

HCOOH + NaOH -> HCOONa + H2O

Question 4

construct equation when Propanoic Acid and Ammonia react together

Answer 4

CH3CH2COOH + NH3 -> CH3CH2COO^- + NH4^+

Question 5

products formed when pentyl propanoate reacts with water

Answer 5

Propanoate + pentan-1-ol

Question 6

Suggest why propane-1,2,3-triol is soluble in water.

Answer 6

H2O can form hydrogen bonds to the delta negative oxygen in the OH bond in propane-1,2,3-triol

Question 7

Triglycerides are esters made when fatty acids react with an alcohol.
What is the name of this alcohol?

Answer 7

Glycerol / propane-1,2,3-triol

Question 8

Biodiesel contains methyl esters of fatty acids. Explain why there is an increased use of biodiesel.

Answer 8

to conserve crude oil supplies
to reduce amount of CO2 released to the atmosphere

Question 9

Outline the mechanism for the reaction between Propanol and Pentanoyl chloride. Name the product.

Answer 9

(same mechanism can also be done if acyl chloride reacts ammonia)

Question 10

Name compound CH3CH2CONH2

Answer 10

Propanamide
- the CONH2 is the amide bond

Question 11

Describe briefly how you could measure the melting point of aspirin.

Answer 11

• Input sample into a capillary / melting tube
• heat gently / slowly near melting point

Question 12

Give two industrial advantages of using ethanoic anhydride rather than ethanoyl chloride in the manufacture of aspirin.

Answer 12

• safer
• less corrosive
• less vulnerable to hydrolysis
• less vigorous
• doesn’t produce HCL
• Less volatile

Question 13

Also name the product formed

Answer 13

CH3CO^+ = intermediate
Phenylethanoate