Important Chemical Reactions
All key balanced chemical equations for BSE Telangana Class 10 Physical Science — acids and bases, metals, carbon compounds, decomposition, and salt preparation reactions.
Acids — Key Reactions
Zn + H₂SO₄ → ZnSO₄ + H₂↑
Metal + Dilute acid → Salt + Hydrogen gas
2HCl + CaCO₃ → CaCl₂ + H₂O + CO₂↑
Acid + Carbonate → Salt + Water + Carbon dioxide
HCl + NaOH → NaCl + H₂O
Neutralisation: acid + base → salt + water
H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O
Sulphuric acid neutralised by sodium hydroxide
HCl + NaHCO₃ → NaCl + H₂O + CO₂↑
Acid + Baking soda — CO₂ released
Metals — Key Reactions
4Na + O₂ → 2Na₂O
Sodium burns in oxygen — very reactive
2Mg + O₂ → 2MgO
Magnesium burns with bright white flame
Fe₂O₃ + 2Al → Al₂O₃ + 2Fe
Thermite reaction — aluminium reduces iron oxide (used in welding)
Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag
Displacement: more reactive Cu displaces less reactive Ag
Fe + CuSO₄ → FeSO₄ + Cu
Iron displaces copper from copper sulphate solution
Carbon Compounds
CH₄ + 2O₂ → CO₂ + 2H₂O
Combustion of methane — complete combustion
C₂H₅OH + O₂ → CH₃COOH + H₂O
Oxidation of ethanol (alcohol) to ethanoic acid (acetic acid)
C₂H₅OH → C₂H₄ + H₂O (conc. H₂SO₄, 443K)
Dehydration of ethanol to ethene
CH₃COOH + C₂H₅OH ⇌ CH₃COOC₂H₅ + H₂O
Esterification — ethanoic acid + ethanol → ethyl ethanoate (ester)
CH₃COOC₂H₅ + NaOH → CH₃COONa + C₂H₅OH
Saponification — ester + base → soap (salt of acid) + alcohol
Decomposition Reactions
2H₂O₂ → 2H₂O + O₂↑ (MnO₂ catalyst)
Decomposition of hydrogen peroxide — oxygen released
CaCO₃ → CaO + CO₂↑ (heat)
Thermal decomposition of limestone — quicklime made
2Pb(NO₃)₂ → 2PbO + 4NO₂↑ + O₂↑ (heat)
Thermal decomposition of lead nitrate
2AgCl → 2Ag + Cl₂↑ (sunlight)
Photolytic decomposition — used in photography
Salts — Preparation and Properties
NaCl + H₂SO₄ → NaHSO₄ + HCl↑ (heat)
Preparation of HCl from common salt
Na₂CO₃ + CO₂ + H₂O → 2NaHCO₃
Solvay process step — washing soda to baking soda
2NaHCO₃ → Na₂CO₃ + H₂O + CO₂↑ (heat)
Baking soda decomposition on heating — why baking powder rises
Ca(OH)₂ + Cl₂ → CaOCl₂ + H₂O
Preparation of bleaching powder from slaked lime