All questions of Chemical Reactions and Equations for Class 9 Exam

• a)
  CaCO₃ → CaO + CO₂
• b)
  H₂ + Cl₂ → 2HCl
• c)
  H₂CO₃ → H₂O + CO₂
• d)
  2KClO₃ → 2KCl + 3O₂

• a)
  NaOH + HCl → NaCl + H₂O
• b)
  NH₄CNO → H₂NCONH₂
• c)
  2KClO₃ → 2KCl + 3O₂
• d)
  H₂ + I₂ → 2HI

• a)
  Combination reaction
• b)
  Oxidation reaction
• c)
  Exothermic reaction
• d)
  All of the above

• a)
  Red litmus solution
• b)
  Lime water
• c)
  A burning splinter
• d)
  Blue litmus solution

• a)
  Decomposition reaction
• b)
  Combination reaction
• c)
  Displacement reaction
• d)
  Single displacement reaction

• A:

  A = 1, B = 1, C = 2, D = 1

• B:

  A = 2, B = 2, C = 2, D = 1

• C:

  A = 2, B = 1, C = 2, D = 1

• D:

  none of these

The answer is b.

• a)
  CaCO₃ → CaO + CO₂
• b)
  CaO + 2HCl → CaCl₂ + H₂O
• c)
  Fe + CuSO₄ → FeSO₄ + Cu
• d)
  NaOH + HCl → NaCl + H₂O

• a)
  4 Na+ O₂ → 2 Na₂O
• b)
  2 Cu + O₂ → 2 CuO
• c)
  Mg + 2 HCl → MgCl₂ + H₂
• d)
  N₂ + 3 H₂ → 2 NH₃

• a)
  Silver
• b)
  Copper
• c)
  Aluminium
• d)
  Iron

• a)
  Decomposition reaction
• b)
  Combination reaction
• c)
  Double displacement reaction
• d)
  Displacement reaction

• a)
  SO₂
• b)
  H₂S
• c)
  H₂O
• d)
  S

• a)
  2H₂ + O₂ → 2H₂O
• b)
  2Mg + O₂ → 2MgO
• c)
  AgNO₃ + NaCl → AgCl + NaNO₃
• d)
  H₂ + Cl₂ →  2HCl

• a)
  decomposition reaction
• b)
  combination reaction
• c)
  displacement reaction
• d)
  double displacement reaction

• a)
  reddish-brown
• b)
  grey 
• c)
  Blue
• d)
  silvery-white

• a)
  rusting of iron
• b)
  milk changes to curd
• c)
  digestion of food in our body
• d)
  changing of water to water vapour

• a)
  decomposition reaction
• b)
  displacement reaction
• c)
  combination reaction
• d)
  double displacement reaction

• a)
  Displacement reaction
• b)
  Combination reaction
• c)
  Double displacement reaction
• d)
  Decomposition reaction

• a)
  Hydrogen gas and Iron chloride are produced
• b)
  Chlorine gas and Iron hydroxide are produced
• c)
  NO reaction takes place
• d)
  Iron salt and water are produced

• a)
  yellow
• b)
  brown
• c)
  black
• d)
  white

• a)
  X = Fe, Y = Fe₂O₃
• b)
  X = Ag, Y = Ag₂S
• c)
  X = Cu, Y = CuO
• d)
  X = Al, Y = Al₂O₃

• a)
  Zn rod became thinner
• b)
  Zn rod became thicker due to iron deposition
• c)
  Zn rod remains as it was
• d)
  Zn rod has holes

• a)
  turns lime water milky
• b)
  makes a burning matchstick burn more brightly
• c)
  burns with a pop sound
• d)
  causes choking and suffocation

• a)
  Ferric oxide, Sulphur dioxide, Sulphur trioxide
• b)
  Ferric oxide, Ferrous sulphide, Oxygen
• c)
  Ferrous sulphide, Sulphur dioxide, Oxygen
• d)
  Ferric oxide, Sulphur trioxide, Oxygen

• a)
  decomposition reaction
• b)
  double displacement reaction
• c)
  combustion reaction
• d)
  combination reaction

• a)
  Zn is most reactive, Fe is least reactive
• b)
  Fe is most reactive, and Cu is least reactive
• c)
  Zn is most reactive, and Cu is least reactive
• d)
  Cu is most reactions, Fe is least reactive

• a)
  SO₂
• b)
  H₂S
• c)
  H₂O
• d)
  S

• a)
  Copper is more reactive than silver.
• b)
  Silver is more reactive than copper.
• c)
  Both are equally reactive.
• d)
  None of these

• a)
  In oxidation, oxygen in added to a substance.
• b)
  In reduction, Hydrogen is added to a substance.
• c)
  Oxidizing agent is oxidized.
• d)
  Reducing agent is oxidized

• a)
  Endothermic reaction
• b)
  Precipitation reaction
• c)
  Exothermic reaction
• d)
  Precipitation and endothermic reaction

• a)
  from colourless to blue
• b)
  from light green to blue
• c)
  from blue to light green
• d)
  from light green to colourless

• a)
  CaO + H₂O → Ca(OH)₂ + Heat - Combination Reaction
• b)
  Fe + 4H₂O → Fe₃O₄ + 4H₂ - Decomposition Reaction
• c)
  3Fe + 4H₂O → Fe₃O₄ + 4H₂ - Combination Reaction
• d)
  CO + 2H₂ → CH₃OH - Displacement Reaction

• a)
  NaCl solution and copper metal
• b)
  MgCl₂ solution and aluminium metal
• c)
  FeSO₄ solution and silver metal
• d)
  AgNO₃ solution and copper metal

• a)
  Rod
• b)
  Powder
• c)
  Filing
• d)
  Granules

• a)
  ZnSO₄
• b)
  FeSO₄
• c)
  Al₂(SO₄)₃
• d)
  Na₂SO₄

• a)
  BaSO₄ and NaO
• b)
  BaCl₂ and Na₂SO₄
• c)
  BaSO₄ and NaCl
• d)
  Na₂SO₄ and NaCl

• a)
  Hissing sound and the solution becomes hot
• b)
  No characteristic sound and solution turns cold
• c)
  Hissing sound and the solution becomes cold
• d)
  No characteristic sound and the solution becomes hot

• a)
  H₂ + O₂ → H₂O
• b)
  2H₂ + O₂ → H₂O
• c)
  H₂ + 2O₂ → H₂O
• d)
   

  2H₂ + O₂ → 2H₂O

• a)
  Combination Reaction
• b)
  Decomposition Reaction
• c)
  Displacement Reaction
• d)
  Double Displacement Reaction

• a)
  Burning of coal - C(s) + O₂(g) → CO(g)
• b)
  Formation of water - 2H₂(g) + O₂(g) → 2H₂O₂(l)
• c)
  Respiration - C₆H₁₂O₆(aq) + 6O₂(aq) → 6CO₂(aq) + 6H₂O₂(l) + energy
• d)
  Whitewashing reaction - Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s) + H₂O(l)

• a)
  Pale green coloured solution turns colourless
• b)
  Colourless solution turned pale green
• c)
  Pale green coloured solution remained pale green
• d)
  Colourless solution turned blue

• a)
  (i)
• b)
  (ii)
• c)
  (iii)
• d)
  (iv)

• a)
  Heat
• b)
  All of these
• c)
  Electricity
• d)
  light

• a)
  If both Assertion and Reason are true and Reason is the correct explanation of Assertion
• b)
  If both Assertion and Reason are true but Reason is not the correct explanation of Assertion
• c)
  If Assertion is true but Reason is false
• d)
  If both Assertion and Reason are false

• a)
  If Assertion is true but Reason is false 
• b)
  If both Assertion and Reason are true but Reason is not the correct explanation of Assertion
• c)
  If both Assertion and Reason are true and Reason is the correct explanation of Assertion
• d)
  If both Assertion and Reason are false

• a)
  AgNO₃ + KI → AgI + KNO₃
• b)
  Pb + CuCl₂ → PbCl₂ + Cu
• c)
  C + O₂ → CO₂
• d)
  SnO₂ + C → Sn + CO₂

• a)
  Compounds are same in both sides
• b)
  Molecules are same in both sides
• c)
  Number of atoms is same in both sides
• d)
  Number of electrons are same in both sides

• a)
  Due to a chemical reaction with air
• b)
  Because of a change in temperature
• c)
  As a result of a displacement reaction
• d)
  Through a physical reaction with water

• a)
  a white precipitate is formed
• b)
  a red precipitate is formed
• c)
  the colour of the solution turns blue
• d)
  a pungent smelling gas is evolved

• a)
  FeSO₄
• b)
  ZnSO₄
• c)
  Al₂(SO₄)₃
• d)
  Both (b) and (c)

• a)
  Combination reaction
• b)
  Decomposition reaction
• c)
  Precipitation reaction
• d)
  None of these