Reactions of Bases

📚 Key Concepts

🔹 Real-Life Example

When you add a few drops of NaOH solution to aluminum foil, you’ll see bubbles forming and the foil dissolving. This shows that bases can also react with certain metals. That’s why drain cleaners (which contain NaOH) are so effective – they dissolve hair and other organic matter!

🧪 Important Reactions

🔸 Base + Metal → Salt + Hydrogen Gas

Examples:

• 2NaOH + 2Al + 6H₂O → 2NaAlO₂ + 3H₂↑
• 2NaOH + Zn → Na₂ZnO₂ + H₂↑

🔸 Base + Non-metal Oxide → Salt + Water

Examples:

• Ca(OH)₂ + CO₂ → CaCO₃ + H₂O
• 2NaOH + CO₂ → Na₂CO₃ + H₂O

Non-metal oxides are acidic in nature, so they neutralize bases.

🔸 Base + Acid → Salt + Water (Neutralization)

Examples:

• NaOH + HCl → NaCl + H₂O
• Ca(OH)₂ + 2HNO₃ → Ca(NO₃)₂ + 2H₂O

🔍 Advanced: Amphoteric Oxides

Some oxides like Al₂O₃ and ZnO can react with both acids and bases, showing both acidic and basic properties. These are called amphoteric oxides.