CBSE BOARD 2024 Chapter -01 Chemical reaction and Equation class 10 (Question Answer)

X Class 10 Chemical reaction and Equation chapter wise MCQ

Section – A (1 mark)

1.  4NH₃ (g) + 5O₂ (g) → 4NO(g) + 6H2O(g) is an example of

 (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)

2. Which of the following statements are correct? 

3Fe(s) + 4H₂O(g) → Fe₃O₄ (s) + 4H₂ (g)

(i) Iron metal is getting oxidised                    

(ii) Water is getting reduced

(iii) Water is acting as reducing agent            

(iv) Water is acting as oxidising agent

(a) (i), (ii) and (iii)        (b) (iii) and (iv)            (c) (i), (ii) and (iv)        (d) (ii) and (iv)

3. 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

(a) (i) and (ii)               (b) (ii) and (iii)             

(c) (i) and (iv)              (d) (iii) and (iv)

4. Which one of the following  is not an exothermic process ?

(a) addition of NaOH in water             (b) addition of Anhydrous CuSO₄ in water 

(c) addition of NaCl in water   d) The decomposition of vegetable matter into compost

5. The light purple colour of acidified permanganate solution fades and finally disappears when a dilute ferrous sulphate solution added into it because

(a) KMnO₄ is oxidises FeSO₄  (b) FeSO₄ oxidises KMnO₄  

(c) no reaction occur                 (d) KMnO₄ decomposes.

6. Exposure of silver chloride to sunlight for a long duration turns grey due to

(A) the formation of silver by decomposition of silver chloride         

(B) sublimation of silver chloride

(C) decomposition of chlorine gas from silver chloride                     

(D) oxidation of silver chloride

7. 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 Recⁿ.  (ii) Precipitation Recⁿ 

(iii) Combination Recⁿ   (iv) Double displacement Recⁿ

(a) (i) only (b)  (ii) only           (c) (iv) only      (d) (ii) and (iv)

8. If aqueous potassium iodide and aqueous lead nitrate react , 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

9. 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

 10. On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed : Identify X  

(a) Sulphur dioxide     (b) Nitrogen oxide      

(c) Nitrogen dioxide    (d) copper oxide

Section – B (2 marks )

11. Write the balanced chemical equations (Any four) and identify the type of reaction in each case.

(a) Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773K to form ammonia gas.

(b) Sodium hydroxide solution is treated with acetic acid to form sodium acetate and water.

(c) Ethanol is warmed with ethanoic acid to form ethyl acetate in the presence of concentrated H₂SO₄ .

(d) Ethene is burnt in the presence of oxygen to form carbon dioxide, water and releases heat and light.

(e) Thermit reaction, iron (III) oxide reacts with aluminium and gives molten iron and aluminium oxide.

(f) Magnesium ribbon is burnt in an atmosphere of nitrogen gas to form solid magnesium nitride.

(g) Chlorine gas is passed in an potassium iodide(aq) solution to form potassium chloride (aq) and solid iodine.

12. Complete the missing components/variables given as x and y in the following reactions

(a) Pb(NO₃)₂ (aq) + 2KI(aq) → PbI₂ (x) + 2KNO₃ (y)            

(b) Cu(s) + 2Ag NO₃ (aq) → Cu(NO₃)₂ (aq) + x(s)

(c) feSO₄(s)    Fe₂O₃(X)  + SO₂ (y) + SO₃ (y)                 

(d) CaCO3 (s) CaO(s) + CO₂ (g)

13.Identify the reducing agent in the following reactions

(a) CuO + H₂ → Cu + H₂O                             (b) CuSO₄ + Zn → Cu + ZnSO₄        

(c) Fe₂O₃ + 3CO → 2Fe + 3CO₂                    (d) 3Fe + 4H₂O → Fe₃O₄ + 4H₂                       

14.How can you day that decomposition reaction is opposite of combination reaction?

15. (A) what do you mean by double displacement reaction. what happens when Copper sulphate treated with potassium iodide? write balance chemical equation.

OR, 15(B) A element X present in bones on treatment with water it forms a solution which turns red litmus blue. Identify X and write the chemical reactions involved.

Section – C  ( 3 marks )

16. A magnesium ribbon is burnt in oxygen to give a white compound X accompanied by emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound Y. (a) Write the chemical formulae of X and Y. (b) Write a balanced chemical equation, when X is dissolved in water.

OR,  16(B) A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining. (a) Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved. (b) Name the black substance formed and give its chemical formula.

17. On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper oxide (black), oxygen gas and a brown gas X is formed (a) Write a balanced chemical equation of the reaction. (b) Identity the brown gas X evolved. (c) Identity the type of reaction. And  What could be the pH range of aqueous solution of the gas X?

18. What do you mean by displacement reaction. What happens when zinc granules are treated with dilute solution of H₂SO₄ , HNO₃ , and NaOH, also write the chemical equations if reaction occurs.

19. (A) On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained. (a) Write a balanced chemical equation of the reaction involved (b) On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?

OR, 19(B) You are provided with two containers made up of copper and aluminium. You are also provided with solutions of dilute HCl, dilute HNO₃ , ZnCl₂. In which of the above containers these solutions can be kept?

20.(A)  (i) In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.

(ii) Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.

(iii) Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

OR, 20 (B) (i) What do you mean corrosion and rancidity. (ii) Why copper vessel after long uses get green coating ? (iii) write two method to protect metal from rusting and two method to prevent food become rancid.

Solution

1.C      2. C     3, A      4. C     5. A      6.A       7.D      8.B       9.D      10.C

11.(i) 3H2 + N2 = 2NH3          (ii) NaOH +CH3COOH = CH3COONa + H2

(iii) C2H5OH +CH3COOH = CH3COOC2H5 + H2O (IV)C2H67 O2 = CO2 + Heat and light

(v) FE2O3  + 2Al = Fe + Al2O3 (VI) Mg + N2 = Mg3N2 (vii) KI + Cl2 = 2KCl + I2

12. (i) x = solid y = Aquous.    (ii) X = Ag (iii)  ) x = solid y =gas (iv) x = Heat           13. H2,Zn,CO,Fe

15.A.CUSO4 + KI = 2CuI + I 2+K2SO4                     15B. X = Ca . Ca + H2O= Ca(OH)2

16A. Mg + O2 = Mgo ,Mg + N2 = Mg3N2 ,  x= MgO, Y= Mg3N2 ; MgO + H2O= Mg(OH)2

16.B) Silver article turn black because silver (Ag) reacts with H2S present in air. And It forms thin black coating of silver sulphide (Ag2S). this phenomena is called corrosion .

2Ag(s) + H2S (g)→Ag2S(s) + H2(g)

17.Cu(NO3)2 ---Heatà 2CUO +O2+4NO2 , x = NO2  , pH = 1 to 7(Acidic)

18. 4Zn(s)+10HNO3(aq)→4Zn(NO3)2(aq)+5H2O(l)+N2O(g)

4Zn(s)+10HNO3(aq)→4Zn(NO3)2(aq)+5H2O(l)+NH4N3(g)

Zn(s)+NaOH(aq)→Na2ZnO2(aq)+H2(g)

19.A) BaCl2 (aq) + Na2SO4(aq) à BaSO4(S) + NaCl,

When HCl added to to above reaction, BaSO4 decomposes and form SO2 and BaCl2

BaSO4 + HCl -à BaCl2 + SO2+H2O

19.(B) HCl and ZnCl2 sored in Copper vessel and HNO3 in aluminium vessel.

20.(A) 2AgNO3 + Cu -à 2Ag + Cu(NO3)2; (iii) Iron displace cu from CuSO4 and form FeSO4

20.B) copper reacts with CO2 gases and moisture present in air to form a mixture of copper carbonate and copper hydroxide [(CuCO3). Cu(OH)2]. This gives a green colour to the vessels.