Alcohols, Phenols and Ethers

CH₃CH(OH)CH₃, CH₃CH(OH)CH₂CH₃

Secondary alcohols have the OH group attached to a carbon atom that is bonded to two other carbon atoms. CH₃CH(OH)CH₃ (propan-2-ol) and CH₃CH(OH)CH₂CH₃ (butan-2-ol) are both secondary alcohols. The others are primary or tertiary alcohols.

Hydrolysis of diazonium salts, Fusion of chlorobenzene with NaOH, Cumene process

Phenols can be prepared by: (1) hydrolysis of diazonium salts with water, (2) fusion of haloarenes like chlorobenzene with NaOH at high temperature and pressure, and (3) the cumene process involving oxidation of cumene. The other options are methods for preparing alcohols, not phenols.

Phenol > Water > Alcohol

Phenol is more acidic than water and alcohol because the phenoxide ion formed after losing H⁺ is stabilized by resonance with the benzene ring. Water is more acidic than alcohol because alkyl groups are electron-donating and destabilize the alkoxide ion formed.

Ethene

When ethanol is heated with concentrated H₂SO₄ at 443 K (170°C), dehydration occurs to form ethene (CH₂=CH₂) and water. At lower temperatures (413 K), diethyl ether would be formed instead. The high temperature favors elimination over substitution.