MCQ CBSE-10 Science
Choose the correct answer,
Q1: The following reaction is an example of a
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g)
(i) displacement reaction
(ii) combination reaction
(iii) redox reaction
(iv) neutralisation reaction
(a) (i) and (iv)
(b) (ii) and (iii)
(c) (i) and (iii)
(d) (iii) and (iv)
Answer
Answer: (c) (i) and (iii)
Q2: Which of the following is true for an unbalanced chemical equation?
(a) Number of atoms is equal on both sides of the equation
(b) Number of atoms is less on the left side of the equation
(c) Number of atoms is more on the right side of the equation
(d) Both (b) and (c).
Answer
Answer: (d) Both (b) and (c).
Q3: Which option denotes a double displacement reaction?
(a) A + B + C
(b) A + B → C
(c) AC + BD → AD + BC
(d) AC + B → AB + C
Answer
Answer: (c) AC + BD → AD + BC
Q4: Which among the following is (are) double displacement reaction(s)?
(i) Pb + CuCl → PbCl2 + Cu
(ii) Na2SO4 + BaCl2 → BaSO4 + 2NaCl
(iii) C + O2 → CO2
(iv) CH4 + 2O2 → CO2 + 2H2O
(a) (i) and (iv)
(b) (ii) only
(c) (i) and (ii)
(d) (iii) and (iv)
Answer
Answer: (b) (ii) only
Q5: The following reaction is used for the preparation of oxygen gas in the laboratory:
2KClO3 (s) →2KCl + 3O2(g)
Which of the following statement about the reaction is correct?
(a) It is a decomposition reaction and endothermic in nature.
(b) It is a combination reaction.
(c) It is a decomposition reaction and accompanied by release of heat.
(d) It is a photochemical decomposition reaction and exothermic in nature.
Answer
Answer: (a) It is a decomposition reaction and endothermic in nature.
Q6: Which of the following is Not True with respect to the neutralisation reaction?
(a) Salt is formed.
(b) Reaction occurs between an acid and a base.
(c) Reactive element displaces less reactive element.
(d) Reactants are in gaseous state.
Answer
Answer: (d) Reactants are in gaseous state.
Q7: Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is
(a) 1 : 1
(b) 2 : 1
(c) 4 : 1
(d) 1 : 2
Answer
Answer: (b) 2 : 1
Q8: Combustion reactions are always
(a) Exothermic
(b) Endothermic
(c) Sometimes exothermic
(d) Both (a) and (b).
Answer
Answer: (a) Exothermic
Q9: Barium chloride on reacting with ammonium sulphate 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
Answer: (d) (ii) and (iv)
Q10: 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
Answer: (d) Heating copper wire in presence of air at high temperature
Q11: 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
Answer: (b) Lead acetate
Q12: In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?
(a) 2H2(l) + O2(l) → 2H2O(g)
(b) 2H2(g) + O2(l) → 2H2O(l)
(c) 2H2(g) + O2(g) → 2H2O(l)
(d) 2H2(g) + O2(g) → 2H2O(g)
Answer
Answer: (d) 2H2(g) + O2(g) → 2H2O(g)
Q13: 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
Answer: (a) (i) and (ii)
Q14: A teacher gave two test tubes to the students, one containing water and the other containing sodium hydroxide. She asked them to identify the test tube containing sodium hydroxide solution. Which one of the following can be used for the identification?
(a) Blue litmus
(b) Red litmus
(c) Sodium carbonate solution
(d) Dilute hydrochloric acid
Answer
Answer: (b) Red litmus
Q15: Which of the following is not 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
Answer: (d) Combustion of Liquefied Petroleum Gas (LPG)
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