Study Notes
Phenols are organic compounds with an -OH group attached to a benzene ring, known for their versatile reactions. They can be synthesized from phenylamine using nitrous acid.
- Phenols — organic compounds with an -OH group attached to a benzene ring Example: Phenol itself, C6H5OH
- Nitrous Acid (HNO2) — an unstable acid used in the synthesis of phenol Example: Formed by reacting sodium nitrite with dilute hydrochloric acid
- Diazonium Salt — an unstable intermediate in phenol production Example: Formed by reacting phenylamine with nitrous acid
- Acid-Base Reaction — a reaction where phenols react with bases to form salts Example: Phenol reacting with sodium hydroxide to form sodium phenoxide
Exam Tips
Key Definitions to Remember
- Phenols are organic compounds with an -OH group attached to a benzene ring.
- Nitrous acid (HNO2) is used to synthesize phenol from phenylamine.
Common Confusions
- Confusing the stability of nitrous acid; it is highly unstable and decomposes easily.
- Mistaking phenol's solubility; it is only slightly soluble in water but dissolves in alkaline solutions.
Typical Exam Questions
- What is the role of nitrous acid in phenol production? It reacts with phenylamine to form a diazonium salt.
- How do phenols react with bases? They form water-soluble salts through acid-base reactions.
- What happens when phenol reacts with reactive metals? A soluble salt and hydrogen gas are formed.
What Examiners Usually Test
- Understanding the synthesis process of phenol from phenylamine.
- The reactions of phenol with bases and reactive metals.