Unit 2

• Inorganic compounds


  Compounds consisting of mineral constituents of the earth or generally found in non-living things
• Inorganic compounds do not contain carbon, although carbon dioxide, carbon monoxide, carbonates and hydrogen carbonates are classified as inorganic compounds
• Examples of inorganic compounds

  • Silicates
  • Oxides
  • Carbonates
  • Sulphides
  • Sulphates
  • Chlorides
  • Nitrates
• Oxides


  Compounds of oxygen with another element (metal, non-metal or metalloid)
• Classification of oxides


  • Acidic oxides
  • Basic oxides
  • Amphoteric oxides
  • Neutral oxides
  • Peroxides
• Acidic oxides


  Non-metal oxides that form acidic solutions when dissolved in water
• Examples of acidic oxides

  • CO2
  • NO2
  • SO2
• Acidic oxides


  • Dissolve in water to form acidic solutions
  • React with basic oxides to form salts
  • React with bases to form salts and water
• Basic oxides


  Metal oxides that dissolve in water and react with it to form basic or alkaline solutions
• Basic oxides


  • Dissolve in water to form alkaline solutions
  • React with acidic oxides to form salts
  • React with acids to form salts and water
• Amphoteric oxides


  Oxides that exhibit both acidic and basic properties
• Amphoteric oxides


  • React with acids to form salts and water
  • React with bases to form salts and water
• Neutral oxides


  Oxides that are neither acidic nor basic
• Examples of neutral oxides

  • CO
  • N2O
• Peroxides


  Oxides containing the peroxide group (-O-O-)
• Peroxides


  • Have strong oxidizing properties
• Acidic, basic and amphoteric oxides can form salts in their reactions
• Indicators like universal indicator and litmus paper can be used to identify acidic and basic oxides
• Acidic oxides react with bases, basic oxides react with acids, but acidic oxides do not react with acids and basic oxides do not react with bases
• Amphoteric oxide


  Substance that behaves as both an acid and a base
• Amphoteric oxide reacting with acid

  Amphoteric oxide + Acid → Salt + Water
• Amphoteric oxide reacting with base

  Amphoteric oxide + Base → Salt + Water
• Amphoteric oxides

  • ZnO, PbO, PbO2, SnO, SnO2
• Amphoteric substance


  Substance that reacts with both acids and bases to form salt and water
• Amphoteric substance


  • Aluminium hydroxide, Al(OH)3
• Acidic oxides, basic oxides and amphoteric oxides are all salt-forming oxides
• Amphoteric behaviour of ZnO and PbO

  1. ZnO/PbO + HCl → Salt + Water

  2. ZnO/PbO + NaOH → Salt + Water

  3. ZnO/PbO + HNO3 → Salt + Water

  4. ZnO/PbO + KOH → Salt + Water
• Objective of the experiment: To observe the amphoteric behaviour of Al2O3
• Neutral oxides react neither with acids nor with bases to form salt and water
• Neutral oxides

  • H2O, CO, N2O, NO
• In peroxides, the oxidation state of oxygen is -1
• Peroxides

  • H2O2, Na2O2, CaO2, BaO2, SrO2
• Formation of peroxides


  1. 2Na + O2 → Na2O2

  2. Ca + O2 → CaO2
• Chemical properties of peroxides

  • Powerful oxidizing agents
  • React with aqueous acids to form hydrogen peroxide
• Hydrogen peroxide decomposes to release oxygen
• Hydrogen peroxide is a strong oxidizing agent
• Objective of the experiment: To identify peroxides from other oxides
• Classification of oxides


  • Acidic
  • Basic
  • Amphoteric
  • Neutral
  • Peroxides
• Reactions of various oxides

  1. BaO + P4O10 →

  2. Al2O3 + HNO3 →

  3. SrO + SO3 →

  4. CO2 + KOH →

  5. ZnO + H3PO4 →

  6. CaO + HCl →

  7. PbO + NaOH →

  8. MgO + H2SO4 →
• Acids that react with water to form HNO3, H2CO3, H2SO4, H2SO3, H3PO4, H3PO3