Q. How do carboxylic acids react to form acyl chlorides?
Carboxylic acids react with sulfur dichloride oxide to form an acyl chloride, sulfur dioxide and hydrogen chloride.
Q. How is methanoic acid further oxidised?
Methanoic acid is a carboxylic acid that contains an aldehyde functional group. This aldehyde group can be further oxidized using Tollens' reagent or Fehling's solution. When oxidized, methanoic acid is converted to carbon dioxide and water.
Q. How is ethanedioic acid oxidised further?
Ethanedioic acid is oxidised to carbon dioxide and water using warm acidified potassium manganate (VII) solution.
Q. Explain the relative acidities of carboxylic acids, alcohols and phenols.
- Carboxylic acids are the most acidic as the carboxylate ion has a delocalised pi system that develops over the -COO group. This distributes the negative charge, making rhe carboxylate ion more stable.
- Phenols are more acidic than alcohols because the phenoxide ion is relatively stable. The lone pair on the oxygen is delocalised into the pi system so the negative charge is dispersed. This makes phenol more likely to donate a hydrogen ion compared with alcohols.
- Alcohols are the least acidic because of the positive inductive effect. In the alkoxide ion, the alkyl groups push electrons away from themselves increasing the electron density of the oxygen making it more likely to bond to a hydrogen ion and reform an alcohol.
Q. What determines the acidity of chlorine substituted ethanoic acids?
Add chlorine atom to the chain. Chlorine is very electronegative and so will have a tendency to attract electrons towards itself. More the chlorines bonded, the stronger the acid.
Q. How do acyl chlorides react with water?
Hydrolysis reaction. The acyl chloride reacts with water to form a carboxylic acid and hydrochloric acid.
Q. How do acyl chlorides react with alcohols?
Acyl chlorides react with alcohols to form an ester and hydrochloric acid.
Q. How do acyl chlorides react with phenol?
An acyl chloride reacts with phenol to form an aromatic ester and hydrochloric acid.
Q. How do acyl chlorides react with ammonia?
Acyl chlorides react with ammonia to form a primary amide and hydrochloric acid.
Q. How do acyl chlorides react with a primary amine?
Acyl chlorides react with a primary amine to form a secondary amide and hydrochloric acid.
Q. Compare the relative ease of hydrolysis of acyl chlorides, alkyl chlorides and aryl chlorides.
- Acyl chlorides react vigorously with cold water to produce a carboxylic acid and hydrogen chloride gas.
- Alkyl chlorides have almost no reaction with water.
- Aryl chlorides have no reaction with water.
Q. How do esters undergo acid hydrolysis?
Heat the ester under reflux with dilute aqueous acid. The ester will be hydrolysed into a carboxylic acid and alcohol. The reaction is slow and reversible.
Q. How do esters undergo base hydrolysis?
Heat the ester under reflux with a dilute alkali. The ester will be hydrolysed into the salt of the carboxylic acid, and the alcohol. The reaction is one-way and faster than acid hydrolysis.
No comments:
Post a Comment