Reactions of carboxylic acids

Question 1

What does the polar nature of carboxylic acids mean?

Answer 1

• open to attacks from nucleus
• the O^δ​- of the C=O may be attacked by a positvely charged species
  
  • like H+ - can be protonated

Question 2

What is the carboxylate ion? How is it formed?

Answer 2

hydrogen of the -OH group is lost, a negative ion - a carboxylate ion - is left

Question 3

Where is teh negative charged located on the carboxylate ion?

Answer 3

the negative charged is shared over the whole carboxylate group

shown by this:

Question 4

What is the properties of the carboxylate ion?

Answer 4

• this delocalisation makes the resulting ion more stable
• carboxylic acids are weak acids
  
  • so the equilibrium between the reversible reaction between the carboxlic acid and the carboxylate ion is well over to the left (towards the carboxylic acid)

Question 5

How can carboxylic acids be distinguished?

Answer 5

• strong enough of an acid so that they can react with sodium hydrogencarbonate
• this reaction releases carbon dioxide
• this distinguishes them from other compound that contain the organic group

Question 6

What is the equation for the reaction of sodium hydrogencarbonate with ethanoic acid?

Answer 6

CH₃COOH (aq) + NaHCO₃ (aq) → CH₃COONa (aq) + H₂O (l) + CO₂ (g)

think of the coon

product is sodium ethanoate, water, and carbon dioxide

Question 7

What are most the reaction of carboxylic acids?

Answer 7

they are proton donors

show the typical reactions of acids

Question 8

WHat are the products of the reactions of carboxylic acids?

Answer 8

• form ionic salts with:
  
  • more reactive metals
  • alkalis
  • metal oxides
  • metal carbonates in the usual way

Question 9

What are the properties of the salts fromed?

Answer 9

• general name carboxylates
  
  • named from the particular acid
  • methanoic acid gives methanoates etc.

Question 10

WHat is the equation for the reaction between ethanoic acid and sodium carbonate?

Answer 10

• 2CH₃COOH(aq) + Na₂CO₃(aq) → 2CH₃COONa(aq) + H₂O(l) + CO₂(g)
• product is sodium ethanoate, water, and carbon dioxide

Question 11

How are carboxylic acids commonly formed?

Answer 11

• reduction of alcohols