CBSE Class 10 Science Chemical Reactions and Equations MCQs Set E

Question: What type of chemical reactions take place when electricity is passed through water?
a) Displacement
b) Combination
c) Decomposition
d) Double displacement
Answer: c
 

Question: When SO₂ gas is passed through saturated solution of H₂S, which of the following reaction occurs?
a) SO₂ + 2H₂S → 2H₂O + 3S
b) SO₂ + 2H₂S → H₂O + 3S
c) SO₂ + H₂S → H₂O + S
d) SO₂ + H₂O → SO₃ + H₂ 
Answer: a

Question: A student added dilute HCl to a test tube containing zinc granules and made following observations which one is correct?
a) The zinc surface became dull and black.
b) A gas evolved which burns with a pop sound.
c) The solution remained colourless.
d) The solution becomes green in colour. 
Answer: b

Question: The reaction in which two compounds exchange their ions to form two new compounds is –
a) a displacement reaction
b) a decomposition reaction
c) an isomerization reaction
d) a double displacement reaction
Answer: d

Question: Which of the following is a combustion reaction ?
a) Boiling of water
b) Melting of wax
c) Burning of petrol
d) None of these
Answer: d

Question: The reaction, Fe₂O₃(s) + 2Al(s) →Al₂O₃ + 2Fe(l) is an example of
a) combination reaction
b) double displacement
c) decomposition reaction
d) single displacement reaction
Answer: d

Question: When copper powder is heated, it gets coated with
a) Black copper oxide
b) Yellow copper oxide
c) Red copper oxide
d) None of these
Answer: a

Question: What is observed when a solution of potassium iodide is added to silver nitrate solution?
a) No reaction takes place
b) White precipitate of silver iodide is formed
c) yellow precipitate of Agl is formed
d) Agl is soluble in water.
Answer: c

Question: The colour of the residue left in the test tube after heating ferrous sulphate which undergoes decomposition is
a) yellowish-brown
b) black
c) white
d) grey
Answer: a

Question: The compound also known as blue vitriol is
a) FeSO₄.7H₂O
b) CuSO₄.5H₂O
c) CaSO₄.2H₂O
d) Na₂CO3.10H₂O
Answer: b

Question: Heating limestone produces
a) Quick lime
b) Carbon dioxide
c) Both Quick lime and Carbon dioxide
d) None of these
Answer: c

Question: Wh ich of the followin g is not a t hermal decomposition reaction ? 
a) 2H₂O →2H₂ + O₂
b) 2FeSO4 → Fe₂O₃ + SO₂ + SO₃
c) ZnCO₃ →ZnO + CO₂
d) 2KClO₃ → 2KCl + 3O₂
Answer: a

Question: What happens when dilute hydrochloric acid is added to iron filings? Tick the correct answer:
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.
Answer: a

Question: Which of the following reactions involves the combination of two elements?
a) CaO + CO₂ → C_aCO₃
b) 4Na + O₂ → 2Na₂O
c) SO₂ + 1/2 O₂→ SO₃
d) NH₃ + HCl → NH₄Cl
Answer: b

Question: The chemical formula of lead nitrate is:
a) KNO₃
b) PbNO₃
c) K(NO₃)₂
d) Pb(NO₃)₂
Answer: d

Question: The reaction of water and quick lime is an example of
a) combination reaction
b) exothermic reaction
c) both combination reaction and exothermic reaction
d) None of these.
Answer: c

Question: Which of the following is a physical change? 
a) Solubility in water
b) Combustibility
c) Aerial oxidation
d) Reaction with water
Answer: a

Question: Which of the following is a decomposition reaction ?
a) NaOH + HCl → NaCl + H₂O
b) NH4CNO → H₂NCONH₂
c) 2KClO₃ → 2KCl + 3O₂
d) H₂ + I2 → 2Hl
Answer: c

Question: The chemical formula for slaked lime is
a) Ca(OH)₂
b) CaCO₃
c) CaO
d) CaHCO₃
Answer: a

Question: Formation of carbon disulphide from carbon and sulphur takes place by 
a) absorption of heat
b) evolution of heat
c) no change in heat content
d) None of the above
Answer: a

Question: A substance added to food containing fats and oils is called:
a) Oxidant
b) Rancid 
c) Coolant
d) Antioxidant 
Answer: d

Question: Zn+ H₂SO₄(dil) → ZnSO₄ + H₂↑ Above reaction is –
a) decomposition reaction
b) single displacement reaction
c) combination reaction
d) synthesis reaction
Answer: b

Question: The reaction between lead nitrate and potassium iodide present in aqueous solutions is an example of visit for Topper's materials 
a) Decomposition Reaction
b) Displacement Reaction
c) Double Displacement Reaction
d) Neutralisation Reaction
Answer: c

Question: An iron nail was dipped in a salt solution. After sometime a reddish brown deposition of the nail was seen. The salt solution could be
a) Silver nitrate
b) Sodium sulphate
c) Aluminium chloride
d) Copper sulphate
Answer: d

Question: When ferrous hydroxide reacts with hydrochloric acid, _______ and H2O are produced.
a) FeCl₃
b) FeCl₂
c) FeCl₄
d) FeCl
Answer: d

Question: What happens when dilute hydrochloric acid is added to iron filings ? Tick the correct answer.
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.
Answer: a

Question: The chemical formula for lime is
a) Ca(OH)₂
b) CaCO₃
c) CaO
d) CaHCO₃ 
Answer: c

Question: An example of a chemical change is _____.
a) formation of clouds.
b) glowing of an electric light.
c) dropping sodium into water.
d) dissolving of salt in water.
Answer: c

Question: A dilute solution of sodium carbonate was added to two test tubes a) containing dil HCl and b) containing dilute NaOH. The correct observation was –
a) a brown coloured gas liberated in test tube A.
b) a brown coloured gas liberated in test tube B.
c) a colourless gas liberated in test tube A.
d) a colourless gas liberated in test tube B. 
Answer: c

Question: Which among the following is not a chemical change?
a) Melting of ice.
b) Carbon cycle.
c) Dehydration of substances.
d) Fermentation of substances.
Answer: a

Question: The condition produced by aerial oxidation of fats and oils in foods marked by unpleasant smell and taste is called:
a) antioxidation
b) reduction
c) rancidity
d) corrosion 
Answer: c

Question: Chemically rust is
a) Hydrated ferrous oxide
b) hydrated ferric oxide
c) only ferric oxide
d) none of these
Answer: b

Question: Which of the following reactions will not take place?
a) Zn + CuSO₄→ ZnSO₃+ Cu
b) 2KBr + Cl₂→KCI+ Br₂
c) Zn + MgSO₄→ ZnSO₄+ Mg
d) Mg + FeSO₄– MgSO₄+ Fe
Answer: c

Question: In the reaction given below, a, b, c and d respectively are aFe2O₃ + bH₂ →cFe + dH₂O 
a) 1, 1, 2, 3
b) 1, 1, 1, 1
c) 1, 3, 2, 3
d) 1, 2, 2, 3
Answer: c

Question:Name the products formed when iron filings are heated with dilute hydrochloric acid
a) Fe (III) chloride and water
b) Fe (II) chloride and water
c) Fe (II) chloride and hydrogen gas
d) Fe (III) chloride and hydrogen gas 
Answer: d

Question: Which of the following are exothermic processes?
(i) Reaction of water with quick lime
(ii) Dilution of an acid
(iii) Evaporation of water
(iv) Sublimation of camphor (crystals)
a) (i) and (ii)
b) (ii) and (iii)
c) (i) and (iv)
d) (ii) and (iv)
Answer: a

Question: Which of the statements about the reaction below are incorrect?
2PbO (s) + C (s) ⎯⎯→ 2Pb (s) + CO₂ (g)
a) Lead is getting reduced.
b) Carbon dioxide is getting reduced.
c) Carbon is getting oxidised.
d) Lead oxide is getting reduced.
(i) (a) and (b)
(ii) (a) and (c)
(iii) (a), b) and (c)
(iv) All
Answer: a

Question: Which of the statements about the reaction below are incorrect ? 
2PbO(s) + C(s) →2Pb(s) + CO₂(g)
(i) Lead is getting reduced.
(ii) Carbon dioxide is getting oxidised.
(iii) Carbon is getting oxidised.
(iv) Lead oxide is getting reduced.
a) (i) and (ii)
b) (i) and (iii)
c) (i), (ii) and (iii)
d) All of the above
Answer: a

Question:. Which of the following statements about the given reaction are correct?
3Fe (s) + 4H₂O (g) → Fe₃O₄ (s) + 4 H₂ (g)
(i) Iron metal is getting oxidized
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as oxidizing agent
a) (i), (ii) and (iii)
b) (ii) and (iv)
c) (i), (ii) and (iv)
d) (ii) and (iv)
Answer: c

Question:. Oxidation is a process which involves
(i) addition of oxygen
(ii) addition of hydrogen
(iii) removal of oxygen
(iv) removal of hydrogen
a) (i) and (ii)
b) (ii) and (iii)
c) (i) and (iv)
d) (ii) and (iv)
Answer: c

Question: Which of the following are chemical changes ?
(i) Digestion of food
(ii) Liquefaction of air
(iii) Ripening of fruit
(iv) Dissolution of sulphur in carbon disulphide
(v) Freezing of water
(vi) Electrolysis of water
a) (i) to (iv) all
b) (i), (iii) & (vi)
c) (i), (iii) & (iv)
d) (iii), (iv) & (vi)
Answer: b

Question: Barium chloride on reacting with ammoniums ulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved ?
(i) Displacement reaction
(ii) Precipitation reaction
(iii) Combination reaction.
(iv) Double displacement reaction
a) (i) only
b) (ii) only
c) (iv) only
d) (ii) and (iv)
Answer: d

Question: Which among the following statement(s) is (are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to 
 (i) the formation of silver by decomposition of silver chloride
(ii) sublimation of silver chloride
(iii decomposition of chlorine gas from silver chloride
(iv) oxidation of silver chloride
a) (i) only
b) (i) and (iii)
c) (ii) and (iii)
d) (iv) only 
Answer: a

Assertion-Reason Questions 

a) Both ‘A’ and ‘R’ are true and ‘R’ is correct explanation of the assertion.
b) Both ‘A’ and ‘R’ are true but ‘R’ is not correct explanation of the assertion.
c) ‘A’ is true but ‘R’ is false.
d) ‘A’ is false and ‘R’ is true.

Question: Assertion: CO + 2H₂ 340 atm→ Δ CH₃OH(l)
Reason: It is combination reaction because CO combines with H₂ to form CH3OH i.e. two substances combine to form a single compound.
Answer: b

Question: Assertion: A. In electrolysis of water volume of hydrogen is twice the volume of oxygen.
Reason: H₂ gas is liberated at cathode and O₂ at anode.
Answer: b

Question: Assertion: A reducing agent is a substance which can accept electron.
Reason: A substance which helps in oxidation is known as oxidising agent.
Answer: d

Question: Assertion: White silver chloride turns grey in sunlight.
Reason: Decomposition of silver chloride in presence of sunlight takes place to form silver metal and chlorine gas.
Answer: a

Question: Assertion: In the following chemical equation, CuO(s) + Zn(s) → ZnO(s) + Cu(s) Zinc is getting oxidised and copper oxide is getting reduced.
Reason: The process in which oxygen is added to a substance is called oxidation whereas the process in which oxygen is removed from a substance is called reduction.
Answer: a

Question: Assertion: All combustion reactions are exothermic.
Reason: Heat is absorbed in endothermic reactions.
Answer: b

Question: Assertion: The reaction, MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂ is an example of redox reaction.
Reason: In this reaction, HCl is reduced to Cl₂ whereas MnO₂ is oxidized to MnCl₂.
Answer: c

Assertion-Reason Questions 

a) Both ‘A’ and ‘R’ are true and ‘R’ is correct explanation of the assertion.
b) Both ‘A’ and ‘R’ are true but ‘R’ is not correct explanation of the assertion.
c) ‘A’ is true but ‘R’ is false.
d) ‘A’ is false and ‘R’ is true. 

Question: Assertion: Iron articles get rusted in moist air.
Reason: Moisture and oxygen required for rusting to form hydrated ferric oxide.
Answer: a

Question: Assertion: Chips and other snacks become rancid due to oxidation.
Reason: To prevent the food like chips and other snacks they are packed in carbon dioxide gas.
Answer: c

Case Study Based Questions

Read the following and answer any four questions from (i) to (v):
In the below experiment, when an iron nail is dipped in copper sulphate solution, a brown coating of copper is formed in the surface of iron and the colour of copper sulphate solution changes from blue to pale green. The reaction shows that iron is more reactive than copper because it displaces copper from the copper sulphate solution.

Question: In the following equation:

Cu + xHNO₃ → Cu(NO₃)₂ + yNO₂ + 2H₂O.
The values of x and y are:
a) 3 and 5
b) 8 and 6
c) 4 and 2
d) 7 and 1
Answer: c

Question: When copper rod is dipped in iron sulphate solution:
a) Copper displaces iron
b) Blue colour of copper sulphate solution is obtained
c) No reaction takes place
d) Reaction is exothermic
Answer: c

Question: A substance which oxidised itself and reduces other is known as:
a) Oxidising agent
b) Reducing agent
c) Both Oxidising agent and Reducing agent
d) None of these
Answer: b

Question:Name the products formed when iron filings are heated with dilute hydrochloric acid.
a) Fe (III) chloride and water
b) Fe (II) chloride and water
c) Fe (II) chloride and hydrogen gas
d) Fe (III) chloride and hydrogen gas
Answer: c