WIM - Phenols Flashcards
How can you test a compound to see if it is a phenol?
Add iron (III) Chloride solution and the solution will turn purple if there is phenol present
Are phenols acidic, alkaline or neutral? Explain your answer
Phenols are weakly acidic because phenol dissociates in water to form a phenoxide ion and an H⁺
Why are phenols reacted with acyl chlorides instead of carboxylic acids to make esters?
Phenols react very slowly with carboxylic acids, so it’s faster to use acyl chlorides
Carboxylic acids and phenols both have pH values below 7, and both react with strong bases such as sodium hydroxide.
Describe two tests that you could use to tell a phenol and a carboxylic acid apart
[6 Marks]
TEST 1: Add sodium carbonate (or other suitable carbonate). The carboxylic acid will fizz (CO₂ produced) but the phenol will not react.
TEST 2: Add iron (III) chloride. The carboxylic aid will not react but the phenol will produce a purple coloured solution.
Give the test used and the results that would be seen if a phenol is present
Add iron (III) chloride solution and shake. A purple colour is formed if a phenol group is present (other phenols give other colours)
Describe and explain the solubility of phenol in water
Phenol dissolves a little in water because the hydroxyl group is able to form hydrogen bonds with other water molecules
Describe and explain the pH of phenol in water
Phenol solution is weakly acidic because the phenol dissociates in water to form a phenoxide ion and an H⁺ ion
Give the products when phenol reacts with a strong base (e.g. NaOH)
phenoxide salt (e.g. sodium phenoxide) and water
Give the products when phenol reacts with a weak base (e.g. Na₂CO₃)
No reaction because sodium carbonate isn’t a strong enough base to remove the hydrogen ion from phenol
Give the functional group for an acyl chloride
-COCl
Give the general formula for an acyl chloride
CnH₂n₋₁OCl
Which end are the carbon atoms numbered from for an acyl chloride?
From the end with the acyl chloride
Give the products for the reaction between phenol and an acyl chloride
Ester and HCl gas
