CBSE Class 10 Science Chemical Reactions and Equations MCQs Set G

Question. Fe₂O₃ + 2Al → Al2O₃ + 2Fe The above reaction is an example of a –
(a) combination reaction
(b) double displacement reaction
(c) decomposition reaction
(d) displacement reaction

Answer: D

Question. White silver chloride in sunlight turns to –
(a) grey
(b) yellow
(c) remain white
(d) red

Answer: A

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 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. What is the colour of CuSO₄.5H₂O?
(a) Blue
(b) Green
(c) White
(d) Yellow

Answer: A

Question. Four students used different ways of burning magnesium ribbon during an experiment as shown below.
The correct way has been followed by student: (Diagram)
(a) I
(b) II
(c) III
(d) IV

Answer: C

Question. Corrosion of metals can be prevented
(a) by coating the metal surface with a paint.
(b) by applying film of grease and oil on the surface of the metal.
(c) by covering the surface of the metal with another metal which is more electropositive.
(d) all of these.

Answer: D

Question. Identify the chemical equation which represents a complete balanced equation for the reaction of barium chloride with sodium sulphate to produce barium sulphate and sodium chloride.
(a) BaCl₂(aq) + Na₂SO₄(aq) BaSO₄(s) + NaCl(aq)
(b) BaCl₂(aq) + Na₂SO₄(aq) 2BaSO₄(s) + 2NaCl(aq)
(c) 2BaCl₂(aq) + Na₂SO₄(aq) 2BaSO₄(s) + NaCl(aq)
(d) BaCl₂(aq) + Na₂SO₄(aq) BaSO₄(s) + 2NaCl(aq)

Answer: D

Question. In which of the following heat is absorbed generally?
(a) Combination reaction
(b) Decomposition reaction
(c) Displacement reaction
(d) Double displacement reaction

Answer: B

Question. Which one of the following processes involve chemical reactions?
(a) Storing of oxygen gas under pressure in a gas cylinder
(b) Liquefaction of air
(c) Keeping petrol in a china dish in the open
(d) Heating copper wire in presence of air at high temperature

Answer: D

Question. When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction is SO₂+ 2H₂S → 2H₂O +3S. Here hydrogen sulphide is acting as -
(a) an oxidising agent
(b) a reducing agent
(c) a dehydrating agent
(d) a catalyst

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 reactions involves the combination of two elements?
(a) CaO + CO₂ → CaCO₃
(b) 4Na + O₂ → 2Na₂O
(c) SO₂ + 1/2 O₂ →SO₃
(d) NH₃ + HCl → NH₄Cl

Answer: B

Question. On the basis of following features, identify the correct option.
(i) This reaction occurs during corrosion.
(ii) This reaction occurs during respiration.
(a) Decomposition reaction
(b) Redox reaction
(c) Combination reaction
(d) Endothermic reaction

Answer: B

Question. Which of the following is termed as oxidizing agent?
(a) Which gives oxygen
(b) Which removes oxygen
(c) Which gives hydrogen
(d) All of the above

Answer: A

Question. Which of the following termed as reducing agent?
(a) Which gives oxygen
(b) Which removes oxygen
(c) Which removes hydrogen
(d) All of the above

Answer: B

Question. In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate?
(a) Lead sulphate (insoluble)
(b) Lead acetate
(c) Ammonium nitrate
(d) Potassium sulphate

Answer: D

Question. Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form its solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed?
(i) It is an endothermic reaction
(ii) It is an exothermic reaction
(iii) The pH of the resulting solution will be more than seven
(iv) The pH of the resulting solution will be less than seven
(a) (i) and(ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (iii) and (iv)

Answer: B

Question. Which of the following is not a physical change?
(a) Boiling of water to give water vapour.
(b) Melting of ice to give water.
(c) Dissolution of salt in water.
(d) Combustion of Liquefied Petroleum Gas (LPG).

Answer: D

Question. When the gases sulphur dioxide and hydrogen sulphide mix in the presence of water, the reaction is SO₂ + 2H₂S → 2H₂O + 2S. Here hydrogen sulphide is acting as –
(a) an oxidising agent
(b) a reducing agent
(c) a dehydrating agent
(d) a catalyst

Answer: B

Question. Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statements(s) is (are) correct?
(i) In beakers A and B, exothermic process has occurred.
(ii) In beakers A and B, endothermic process has occurred.
(iii) In beaker C exothermic process has occurred.
(iv) In beaker C endothermic process has occurred.
(a) (i) only
(b) (ii) only
(c) (i) and (iv)
(d) (ii) and (iii)

Answer: C

Question. Which of the following is not a physical change?
(a) Boiling of water to give water vapour
(b) Melting of ice to give water
(c) Dissolution of salt in water
(d) Combustion of Liquefied Petroleum Gas (LPG)

Answer: D

Question. In the following equations :
Na₂CO₃+ x HCl →2NaCl +CO₂+ H₂O, the value of x is-
(a) 1
(b) 2
(c) 3
(d) 4 

Answer: B

Question. Fe₂O₃+ 2Al → Al₂O₃+ 2Fe The above reaction is an example of a-
(a) combination reaction
(b) double displacement reaction
(c) decomposition reaction
(d) displacement reaction 

Answer: D

Question. A student while heating solid lead nitrate taken in a test tube would observe
(a) white residue of PbO₂
(b) green residue of NO₂
(c) yellow residue of PbO
(d) brown residue of NO

Answer: C

Question. Which of the following is (are) an endothermic processes?
(i) Dilution of sulphuric acid. (ii) Sublimation of dry ice.
(iii) Condensation of water vapours. (iv) Evaporation of water.
(a) (i) and (iii)
(b) (ii) only
(c) (iii) only
(d) (ii) and (iv)

Answer: D

Question. A student strongly heats hydrated ferrous sulphate salt in a dry test tube. He would observe a:
(a) yellow residue
(b) brown residue
(c) light green residue
(d) white residue

Answer: B

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) (iii) and (iv)

Answer: A

Question. In which of the following heat is evolved?
(a) Combination reaction
(b) Decomposition reaction
(c) Displacement reaction
(d) Double displacement reaction

Answer: A

Question. What happens 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

Assertion-Reason Questions

In the following question, a statement of Assertion
(a) If both Assertion and Reason are correct and Reason is the correct explanation of Assertion.
(b) If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion.
(c) If Assertion is correct but Reason is incorrect.
(d) If Assertion is incorrect but Reason is correct.

Question. Assertion: When a mixture of hydrogen and chlorine is placed in sunlight, hydrogen chloride is formed.
Reason : It is an example of combination reaction.

Answer: A

Question. Assertion : When copper strip is placed in ferrous sulphate solution, colour of the solution changes.
Reason : Iron is more reactive than copper. 

Answer: D

Question. Assertion : Stannous chloride gives grey precipitate with mercuric chloride, but stannic chloride does not do so.
Reason : Stannous chloride is a powerful oxidising agent which oxidises mercuric chloride to mercury.

Answer: C

Question. Assertion : Corrosion of iron is commonly known as rusting.
Reason : Corrosion of iron occurs in presence of water and air.

Answer: B

True or False :

Question. Oxidation is the loss of electrons from a substance.
Answer: True

Question. Action of heat on ferrous sulphate is an example of decomposition reaction.
Answer: True

Question. Reduction is the gain of electrons by a substance. 
Answer: True

Question. A complete chemical equation represents the reactants, products and their physical states symbolically.
Answer: True