Carboxylic Acids

Question 1

What is the functional group of Carboxylic Acid?

Answer 1

-COOH

Question 2

What do carboxylic acids end in?

Answer 2

-anoic acid

Question 3

What are the first four carboxylic acids and their formulas?

Answer 3

Methanoic acid: HCOOH
Ethanoic acid: CH3COOH
Propanoic acid: C2H5COOH
Butanoic acid: C3H7COOH

Question 4

What type of acid are the carboxylic acids? - what does this mean?

Answer 4

Weak acids - they don’t fully dissociate

Question 5

How are carboxylic acids formed?

Answer 5

Oxidation of alcohols using an oxidising agent

Question 6

What is produced in the oxidation reaction of alcohol? (e.g. ethanol + copper(II) oxide)

Answer 6

Carboxylic acid, water and metal produced (ethanoic acid, water and copper)

Question 7

What happens in a reaction with carboxylic acid and a metal? (e.g. propanoic acid + magnesium →)

Answer 7

Salt and hydrogen is produced (magnesium propanoate + hydrogen)

Question 8

What happens in a reaction with carboxylic acid and a metal carbonate? (e.g. ethanoic acid + calcium carbonate →)

Answer 8

Salt, water and carbon dioxide produced (calcium ethanoate + carbon dioxide + water)

Question 9

ethanoic acid + sodium hydroxide →

Answer 9

sodium ethanoate + water

Question 10

What’s the pH of ethanoic acid?

Answer 10

between 3 and 4

Question 11

What happens when alcohols are exposed to air? (e.g. ethanol)

Answer 11

• OXIDATION
• Ethanol collides with the oxygen in the air and removes 2 hydrogens from the carbon
• One of the oxygens forms a double bond, which makes your carboxylic acid (ethanoic acid)
• The 2 hydrogens that have been removed react with the remaining oxygen to form H2O (water)

Question 12

What’s an example of an oxidising agent that can be used to oxidise an alcohol?

Answer 12

Potassium Dichromate