Class 10th Science | Unit-1 | Chemical Reactions and Equations by Raza Sir

                  CLASS 10TH 


             SUBJECT -SCIENCE 


                   CHAPTER - 1


  Chemical Reactions and Equations 

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Objective type question answer (multiple choice)

Introduction 


1.👉 The name of (NH4)3PO4 is-
➡️ (A) Ammonium Phosphate                  (b) Ammonium Phosphite
      (c) Ammonium Phosphide                  (d) Nitrogen Pentaoxide

2.👉 The formula of carbon monoxide is-
➡️(a) CO2                                                  (b) C2O
    (c) C2O3                                                (D) CO


3.👉 One of the following does not happen during a chemical reaction. This is :-
➡️(a) Breaking of old chemical bonds and formation of new chemical bonds
     (b) Formation of new substances with entirely different properties
     (C) Atoms of one element change into those of another element to form new products,
      (d) A rearrangement of atoms takes place to form new products.

4.👉 Which of the following does not involve a chemical reaction -
➡️(a) digestion of food in our body
     (b) process of respiration
     (c) burning of candle wax when heated
     (D)  melting of candle wax on heating


5.👉 The chemical reaction between two substances is characterised by a change in colour from orange to green.
These two substances are most likely to be :-
➡️(A) Potassium Dichromate solution and Sulphur Dioxide
     (b) Potassium Permanganate solution and Sulphur Dioxide
    (c) Potassium Permanganate solution and Lemon Juice
    (d) Potassium Dichromate solution and Carbon Dioxide.

6.👉 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)                     [NCERT Exemp. Q. 1, Page 1]

                                                                

7.👉 Which one of the following processes involve chemical reactions-
➡️ (a) Storing of oxygen gas under pressure in a gas cylinder
     (b) Liquification of air
     (c) Keeping petrol in a china dish in the open
     (D) Heating copper wire in presence of air at high temperature.  [NCERT Exemp. Q. 16, Page 4]                                                            

 Chemical Equations 

8.👉 The substance that take part in a reaction are called-
 ➡️(a) Reactants and Products
     (b) Products
     (C) Reactants
     (d) None of these


 Balanced Chemical Equations 

9.👉 Which of the following is not a balanced chemical equation -
➡️(a) Mg (s) + CuSO4 (aq) -->MgSO4(aq)+Cu(s)
    (B) Fe (s) + Cl2(g) --> FeCl3 (s)
    (c) Ca(OH)2 (l)+CO2 (g) -->CaCO (s) + H2O(l)
    (d) Zn (s)+H2SO4(aq) -->ZnSO4(aq) + H2(g)

10.👉 The chemical equations are balanced to satisfy one of the following laws in chemical reactions. This law is known as-
➡️(a) law of conservation of momentum
    (B) law of conservation of mass
    (c) law of conservation of motion
    (d) law of conservation of magnetism



Types of Chemical Reactions-

 Combination Reaction 

11.👉 Which of the following is a combination reaction-
   ➡️ (a) CaCO3 (s) + 2HCl (aq) -->CaCl2(s) + CO2(g) + H2O(l)
        (B) N2(g) + 3H2(g) -->2NH3(g)
        (c) 2KNO3(s) -->2KNO2(aq) + O2(g)
        (d) Zn(s) + H2SO4(aq) --> ZnSO4(aq) + H2(g)

12.👉 The chemical formula of lead sulphate is-
➡️ (A) PbSO4                                  (b) Pb(SO4)2
      (c) Pb2SO4                                (d) None of these
    
13.👉 The reaction H2 (g) + Cl2 (g) —> 2HCl (g) is a-
 ➡️(a) Decomposition Reaction
     (B) Combination Reaction
     (c) Double Displacement Reaction
     (d) Displacement Reaction

14.👉 The chemical reaction between quicklime and water is characterised by:-
 ➡️(a) Evolution of hydrogen gas
     (b) Formation of slaked lime precipitate
     (C) Change in temperature of mixture
     (d) Change in colour of the product

15.👉 One of the following is an endothermic reaction. This is :-
➡️(a) combination of carbon and oxygen to form carbon monoxide
     (B) combination of nitrogen and oxygen to form nitrogen monoxide
     (c) combination of glucose and oxygen to form carbon dioxide and water
     (d) combination of zinc and hydrochloric acid to form zinc chloride and hydrogen


16.👉 One of the following is an exothermic reaction. This is-
➡️(a) electrolysis of water
     (b) conversion of limestone into quickdime
     (C)  process of respiration
     (d) process of photosynthesis

17.👉 Consider the following equation of the chemical reaction of a metal M:
               4M + 3O2 --> 2M2O3
            This equation represents:-
➡️  (a) combination reaction as well as reduction reaction
       (b) decomposition reaction as well as oxidation reaction
       (c) oxidation reaction as well as displacement reaction
       (D) combination reaction as well as oxidation reaction

18.👉 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)
                       [NCERT Exempt. Q. 4, Page 1]
➡️        (A) (i) and (ii)
             (b) (ii) and (iii)
             (c) (i) and (iv)
             (d) (iii) and (iv)


 Decomposition Reaction 

19.👉 The chemical symbol for silver is-
     ➡️(a) Sn                                           (b) Au
         (C) Ag                                          (d) Si

20.👉 When calcium carbonate is heated, lime and carbondioxide are formed. This reaction is shown  by the chemical equation-
 ➡️(a) CaCO3 (s) + CO2(g) --> CaO (s)
     (b) CaCO3 (s) + CaO (s) --> CO2 (g)
     (C) CaCO3 (s) -->CaO (s) + CÓ2 (g)
     (d) None of these

21.👉 Which of the following is a decomposition reaction-
➡️(a) NaOH (aq) + HCl(aq) -->NaCl(aq) +H2O(l)
     (b) NH4NCO (s) -->H2NCONH2(s)
     (C) 2KCIO3 (s)-->2KCl (s) + 3O2 (g)
     (d) H2 (g) +I2 (g)

22.👉 Which of the following can be decomposed by the action of light-
     ➡️ (a) NaCl                                       (b) KCI
          (C) AgCl                                      (d) CuCl

23.👉 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                 [NCERT Exemp. Q.11, Page 3]
     
                                                                                             
24.👉 Which of the following is (are) an endothermic process(es)-
(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)        [NCERT Exemp. Q. 12, Page 3]  
                                                                                              

 Displacement Reaction 

25.👉You are given the solution of lead nitrate. In order to obtain a yellow precipitate you should mix with it a solution of:-
➡️(a) Potassium Chloride                   (b) Potassium Nitride
    (c) Potassium Sulphide                   (D) Potassium Iodide

26.👉 Fe2O3 + 2Al --> AL2O3 + 2 Fe
            The above reaction is an example of a
➡️(a) Combination Reaction
     (b) Double Displacement Reaction
     (c) Decomposition Reaction
     (D) Displacement Reaction

27.👉 Which of the following is a displacement reaction -
➡️(a) CaCO3(s) --> CaO (s) + CO2 (g)
    (b) CaO (s) + 2HCl (aq)-->CaCl2 (s) + H2O (l)
    (C) Fe (s) +CuSO4 (aq) -->FeSO4 (aq)+ Cu(s)
    (d) NaOH(aq) + HCl(aq) -->NaCl (aq)+ H2O(l)

28.👉 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
                                                                        ( NCERT EX Q.3, Page 15)

 Double Displacement Reaction 

29.👉 A white precipitate can be obtained by adding dilute sulphuric acid to:
➡️ (a) CuSO4 solution                       (b) NaCl solution
      (C)  BaCl2  solution                      (d) Na2 SO4 solution

30.👉A white precipitate will be formed if we add common salt solution to :
➡️ (a) Ba(NO3)2 solution                       (b) KNO3 solution
      (C) AgNO3 solution                            (d) Mg(NO3)2 solution

31.👉 Consider the reaction :
            KBr (aq) + AgNO3 (aq)→KNO3 (aq)+ AgBr(s)
            This is an example of:-
 ➡️ (a) decomposition reaction                          (b) combination reaction
      (C) double displacement reaction                (d) displacement reaction

32.👉 Which among the following is (are) double displacement reaction-
(i) Pb + CuCl2 → 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)            [NCERT Exemp. Q. 7, Page 2]
                                        

 Oxidation and Reduction 

33.👉 Which of the statements about the reaction below are incorrect-
      2 PbO (s) + C(s) --> 2 Pb (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

34.👉 Which of the following is a redox reaction -
➡️(a) CaCO3 (s) --> CaO (s) + CO2 (g)
     (b) H2 (g) + CI2 (g) --> 2HCl (g)
     (C) CaO (s) + 2HCl (aq) -->CaCl2 (s) +H2O (l)
     (d) Ca(OH)2 (aq) + 2HCl (aq)-->CaCl2 (s)+2H2O (l)
         
35.👉 in the reaction, SO2(g) + 2H2S (g) --> 2H2 (g) + S (s), the reducing agent is-
➡️ (A) H2S                                                       (b) S      
      (c) H2O                                                      (d) SO2   

36.👉 Oxidation is a process which involves-
➡️(A) adition of oxygen                                 (b) addition of hydrogen
     (c) gain of electrons                                   (d) none of these

37.👉 Reduction is a process which involves-
➡️(a) removal of hydrogen                              (b) addition of oxygen
     (C) gain of electron                                     (d) removal of electron

38.👉 The removal of oxygen from a substance is called :-
➡️  (a) oxidation                                               (b) rancidity
       (c) corrosion                                              (D) reduction

39.👉 In the context of redox reactions, the removal of hydrogen from a substance is known as:-
➡️(A) oxidation                                                 (b) dehydration
     (c) reduction                                                 (d) dehydrogenation

40.👉 The process of respiration is:-
➡️  (a) an oxidation reaction which is endothermic
        (b) a reduction reaction which is exothermic
       (c) a combination reaction which is endothermic
       (D) an oxidation reaction which is exothermic

41.👉 You are given the following chemical equation :
                Mg(s) + CuO (s) -->MgO (s) + Cu (s)
This equation represents :-
➡️ (a) decomposition reaction as well as displacement reaction
      (b) combination reaction as well as double displacement reaction
     (C) redox reaction as well as displacement reaction
     (d) double displacement reaction as well as redox reaction

 Corrosion 

42.👉 The chemical reaction involved in the corrosion of iron metal is that of:-
➡️(a) oxidation as well as displacement
    (b) reduction as well as combination
    (C) oxidation as well as combination
    (d) reduction as well as displacement

 Rancidity 

43.👉 The term used to indicate the development of unpleasant smell and taste in fat and oil containing foods due to aerial oxidation is:-
➡️ (a) acidity                                                           (b) radioactivity
      (c) rabidity                                                        (D) rancidity

44.👉 In order to prevent the spoilage of potato chips, they are packed in plastic bags in an atmosphere of:-
➡️  (a) H2                                                                (B) N2
      (c) Cl2                                                                (d) O2

45.👉 Which of the following gases can be used for storage of fresh sample of an oil for a long time-
➡️    (A) Carbon dioxide or oxygen
         (B) Nitrogen or oxygen
         (C) Carbon dioxide or helium
         (D) Helium or nitrogen
                                                   [NCERT Exemp. Q. 14, Page 4]
                         
             ðŸŒŸðŸŒŸðŸŒŸ End of Chapter-1 🌟🌟🌟

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