Which of the following compounds reacts with acids to give salts?

The correct answer is Option (3) → Amines

• Amines are basic due to the lone pair on nitrogen.
• They react with acids (like HCl, H₂SO₄) to form ammonium salts:

$RNH_2 + HCl \rightarrow RNH_3^+ Cl^-$

• Ethers → generally inert to acids.
• Phenols → react with bases, not acids.
• Carbonyl compounds → react with nucleophiles, not acids to give salts.

Hence, the correct answer is Amines.