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Class 9 Chemistry Electrochemistry (b) Balance the following equations by oxidation number method(ix) \mathrm{NaCl}+\mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{MnO}_{2} \rightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}+\mathrm{MnSO}_{4}+\mathrm{


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(b) Balance the following equations by oxidation number method(ix) \mathrm{NaCl}+\mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{MnO}_{2} \rightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}+\mathrm{MnSO}_{4}+\mathrm{H}_{2} \mathrm{O}+\mathrm{Cl}_{2}

21. In electroplating of silver from where \mathrm{Ag}^{+} ions come and where they deposit?
21. In electroplating of silver from where  \mathrm{Ag}^{+} ions come and where they deposit?

21. In electroplating of silver from where \mathrm{Ag}^{+} ions come and where they deposit?

2. Which one is Alloy.(a) Graphite(b) Mercury(c) Steel(d) Water
2. Which one is Alloy.(a) Graphite(b) Mercury(c) Steel(d) Water

2. Which one is Alloy.(a) Graphite(b) Mercury(c) Steel(d) Water

(c) Calculate the oxidation number of chromium in the following compounds.(i) \mathrm{CrCl}_{3}
(c) Calculate the oxidation number of chromium in the following compounds.(i)  \mathrm{CrCl}_{3}

(c) Calculate the oxidation number of chromium in the following compounds.(i) \mathrm{CrCl}_{3}

4. What is Alloy? Explain its classification with examples.
4. What is Alloy? Explain its classification with examples.

4. What is Alloy? Explain its classification with examples.

9. \mathrm{lg} equivalent weight of \mathrm{Al} is equal to(a) 9 \mathrm{~g} (b) 27 \mathrm{~g} (c) 54 \mathrm{~g} (d) \mathrm{lg}
9.  \mathrm{lg}  equivalent weight of  \mathrm{Al}  is equal to(a)  9 \mathrm{~g} (b)  27 \mathrm{~g} (c)  54 \mathrm{~g} (d)  \mathrm{lg}

9. \mathrm{lg} equivalent weight of \mathrm{Al} is equal to(a) 9 \mathrm{~g} (b) 27 \mathrm{~g} (c) 54 \mathrm{~g} (d) \mathrm{lg}

Q.15 Will the reaction be spontaneous for the following set of half reactions.What will be the value of E_{\text {cell }} ?(i) \mathrm{Cr}^{3+}{ }_{(\mathrm{aq})}+3 \mathrm{e}^{-} \rightarrow \mathrm{Cr}_{(\mathrm{s})} (ii) \mathrm{MnO}_{2(3)}+4 \mathrm{H}^{+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Mn}^{2+}{ }_{\text {(a) })}+2 \mathrm{H}_{2} \mathrm{O}_{(0)} (Standard reduction potential for reaction(i) =-0.74 \mathrm{~V} and for the reaction (ii) =+1.28 \mathrm{~V} ).
Q.15 Will the reaction be spontaneous for the following set of half reactions.What will be the value of  E_{\text {cell }}  ?(i)  \mathrm{Cr}^{3+}{ }_{(\mathrm{aq})}+3 \mathrm{e}^{-} \rightarrow \mathrm{Cr}_{(\mathrm{s})} (ii)   \mathrm{MnO}_{2(3)}+4 \mathrm{H}^{+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Mn}^{2+}{ }_{\text {(a) })}+2 \mathrm{H}_{2} \mathrm{O}_{(0)} (Standard reduction potential for reaction(i)  =-0.74 \mathrm{~V}  and for the reaction (ii)  =+1.28 \mathrm{~V}  ).

Q.15 Will the reaction be spontaneous for the following set of half reactions.What will be the value of E_{\text {cell }} ?(i) \mathrm{Cr}^{3+}{ }_{(\mathrm{aq})}+3 \mathrm{e}^{-} \rightarrow \mathrm{Cr}_{(\mathrm{s})} (ii) \mathrm{MnO}_{2(3)}+4 \mathrm{H}^{+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Mn}^{2+}{ }_{\text {(a) })}+2 \mathrm{H}_{2} \mathrm{O}_{(0)} (Standard reduction potential for reaction(i) =-0.74 \mathrm{~V} and for the reaction (ii) =+1.28 \mathrm{~V} ).

7. Nelsons cell is used to prepare caustic soda along with gases. Which of the following gas is produced at cathode:(a) \mathrm{Cl}_{2} (b) \mathrm{H}_{2} (c) \mathrm{O}_{3} (d) \mathrm{O}_{2}
7. Nelsons cell is used to prepare caustic soda along with gases. Which of the following gas is produced at cathode:(a)  \mathrm{Cl}_{2} (b)  \mathrm{H}_{2} (c)  \mathrm{O}_{3} (d)  \mathrm{O}_{2}

7. Nelsons cell is used to prepare caustic soda along with gases. Which of the following gas is produced at cathode:(a) \mathrm{Cl}_{2} (b) \mathrm{H}_{2} (c) \mathrm{O}_{3} (d) \mathrm{O}_{2}

1. Describe the dry cell with diagram.
1. Describe the dry cell with diagram.

1. Describe the dry cell with diagram.

8. In Daniel cell is used as cathode.(a) Zn(b) \mathrm{Cu} (c) \mathrm{Sn} (d) \mathrm{Pb}
8. In Daniel cell is used as cathode.(a) Zn(b)  \mathrm{Cu} (c)  \mathrm{Sn} (d)  \mathrm{Pb}

8. In Daniel cell is used as cathode.(a) Zn(b) \mathrm{Cu} (c) \mathrm{Sn} (d) \mathrm{Pb}

Q.3 Mark the following statements true or false.(i) In electrolytic conduction electrons flow through the electrolyte.(ii) In the process of electrolysis the electrons in the external circuit flow from cathode to anode.(iii) Sugar is a non-electrolyte in solid form and when dissolved in water will allow the passage of an electric current.(iv) A metal will only allow the passage of an electric current when it is in cold state.(v) The electrolytic products of aqueous copper (II) chloride solution are copper and chlorine.
Q.3 Mark the following statements true or false.(i) In electrolytic conduction electrons flow through the electrolyte.(ii) In the process of electrolysis the electrons in the external circuit flow from cathode to anode.(iii) Sugar is a non-electrolyte in solid form and when dissolved in water will allow the passage of an electric current.(iv) A metal will only allow the passage of an electric current when it is in cold state.(v) The electrolytic products of aqueous copper (II) chloride solution are copper and chlorine.

Q.3 Mark the following statements true or false.(i) In electrolytic conduction electrons flow through the electrolyte.(ii) In the process of electrolysis the electrons in the external circuit flow from cathode to anode.(iii) Sugar is a non-electrolyte in solid form and when dissolved in water will allow the passage of an electric current.(iv) A metal will only allow the passage of an electric current when it is in cold state.(v) The electrolytic products of aqueous copper (II) chloride solution are copper and chlorine.

4. Differentiate between oxidizing and reducing agents
4. Differentiate between oxidizing and reducing agents

4. Differentiate between oxidizing and reducing agents

Q.1 Multiple choice questions.(v) If a strip of Cu metal is placed in a solution of \mathrm{FeSO}_{4} :(a) Cu will be deposited(b) Fe is precipitated out(c) Cu and Fe both dissolve(d) No reaction take place
Q.1 Multiple choice questions.(v) If a strip of Cu metal is placed in a solution of  \mathrm{FeSO}_{4}  :(a) Cu will be deposited(b) Fe is precipitated out(c) Cu and Fe both dissolve(d) No reaction take place

Q.1 Multiple choice questions.(v) If a strip of Cu metal is placed in a solution of \mathrm{FeSO}_{4} :(a) Cu will be deposited(b) Fe is precipitated out(c) Cu and Fe both dissolve(d) No reaction take place

(b) Balance the following ionic equations by ion-electron method.(iv) \mathrm{Cu}+\mathrm{NO}_{3}^{1-} \rightarrow \mathrm{Cu}^{2+}+2 \mathrm{NO}_{2}
(b) Balance the following ionic equations by ion-electron method.(iv)  \mathrm{Cu}+\mathrm{NO}_{3}^{1-} \rightarrow \mathrm{Cu}^{2+}+2 \mathrm{NO}_{2}

(b) Balance the following ionic equations by ion-electron method.(iv) \mathrm{Cu}+\mathrm{NO}_{3}^{1-} \rightarrow \mathrm{Cu}^{2+}+2 \mathrm{NO}_{2}

Q.12 Explain the difference between(b) Electrolytic cell and voltaic cell
Q.12 Explain the difference between(b) Electrolytic cell and voltaic cell

Q.12 Explain the difference between(b) Electrolytic cell and voltaic cell

10. Why does the anode carries negative charge in galvanic cell but positive charge in electrolytic cell? Justify with comments.
10. Why does the anode carries negative charge in galvanic cell but positive charge in electrolytic cell? Justify with comments.

10. Why does the anode carries negative charge in galvanic cell but positive charge in electrolytic cell? Justify with comments.

(b) Balance the following equations by oxidation number method(iii) \mathrm{Br}_{2}+\mathrm{NaOH} \rightarrow \mathrm{NaBr}+\mathrm{NaBrO}_{3}+\mathrm{H}_{2} \mathrm{O}
(b) Balance the following equations by oxidation number method(iii)  \mathrm{Br}_{2}+\mathrm{NaOH} \rightarrow \mathrm{NaBr}+\mathrm{NaBrO}_{3}+\mathrm{H}_{2} \mathrm{O}

(b) Balance the following equations by oxidation number method(iii) \mathrm{Br}_{2}+\mathrm{NaOH} \rightarrow \mathrm{NaBr}+\mathrm{NaBrO}_{3}+\mathrm{H}_{2} \mathrm{O}

19. In electroplating of chromium which salt is used as an electrolyte?
19. In electroplating of chromium which salt is used as an electrolyte?

19. In electroplating of chromium which salt is used as an electrolyte?

(d) Calculate the oxidation numbers of the elements underlined in the following compounds.(ii) \mathrm{Na}_{2} \mathrm{CO}_{3}
(d) Calculate the oxidation numbers of the elements underlined in the following compounds.(ii)  \mathrm{Na}_{2} \mathrm{CO}_{3}

(d) Calculate the oxidation numbers of the elements underlined in the following compounds.(ii) \mathrm{Na}_{2} \mathrm{CO}_{3}

(b) Balance the following equations by oxidation number method(vi) \mathrm{HNO}_{3}+\mathrm{HI} \rightarrow \mathrm{NO}+\mathrm{H}_{2} \mathrm{O}+\mathrm{I}_{2}
(b) Balance the following equations by oxidation number method(vi)   \mathrm{HNO}_{3}+\mathrm{HI}  \rightarrow \mathrm{NO}+\mathrm{H}_{2} \mathrm{O}+\mathrm{I}_{2}
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(b) Balance the following equations by oxidation number method(vi) \mathrm{HNO}_{3}+\mathrm{HI} \rightarrow \mathrm{NO}+\mathrm{H}_{2} \mathrm{O}+\mathrm{I}_{2}

8. During the formation of water from hydrogen and oxygen which of the following does not occur:(a) Hydrogen has oxidized(b) Oxygen has reduced(c) Oxygen gains electrons(d) Hydrogen behaves as oxidizing agent
8. During the formation of water from hydrogen and oxygen which of the following does not occur:(a) Hydrogen has oxidized(b) Oxygen has reduced(c) Oxygen gains electrons(d) Hydrogen behaves as oxidizing agent
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8. During the formation of water from hydrogen and oxygen which of the following does not occur:(a) Hydrogen has oxidized(b) Oxygen has reduced(c) Oxygen gains electrons(d) Hydrogen behaves as oxidizing agent

(b) Balance the following equations by oxidation number method(vii) \mathrm{Cu}+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow \mathrm{CuSO}_{4}+\mathrm{SO}_{2}+\mathrm{H}_{2} \mathrm{O}
(b) Balance the following equations by oxidation number method(vii)  \mathrm{Cu}+\mathrm{H}_{2} \mathrm{SO}_{4}  \rightarrow \mathrm{CuSO}_{4}+\mathrm{SO}_{2}+\mathrm{H}_{2} \mathrm{O}
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(b) Balance the following equations by oxidation number method(vii) \mathrm{Cu}+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow \mathrm{CuSO}_{4}+\mathrm{SO}_{2}+\mathrm{H}_{2} \mathrm{O}

2. Define reduction in terms of loss or gain of oxygen or hydrogen. Give an example.
2. Define reduction in terms of loss or gain of oxygen or hydrogen. Give an example.
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2. Define reduction in terms of loss or gain of oxygen or hydrogen. Give an example.

Q.14 Write comprehensive notes on:(c) Alkaline silver oxide and nickel-cadmium batteries fuel cell.
Q.14 Write comprehensive notes on:(c) Alkaline silver oxide and nickel-cadmium batteries fuel cell.
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Q.14 Write comprehensive notes on:(c) Alkaline silver oxide and nickel-cadmium batteries fuel cell.

1. Spontaneous chemical reactions take place in:(a) Electrolytic cell(b) Galvanic cell(c) Nelsons cell(d) Downs cell
1. Spontaneous chemical reactions take place in:(a) Electrolytic cell(b) Galvanic cell(c) Nelsons cell(d) Downs cell
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1. Spontaneous chemical reactions take place in:(a) Electrolytic cell(b) Galvanic cell(c) Nelsons cell(d) Downs cell

(b) Balance the following ionic equations by ion-electron method.(x) \mathrm{CN}^{-}+\mathrm{MnO}_{4}^{1 \cdot} \rightarrow \mathrm{CNO}^{-}+\mathrm{MnO}_{2(\mathrm{~s})}
(b) Balance the following ionic equations by ion-electron method.(x)   \mathrm{CN}^{-}+\mathrm{MnO}_{4}^{1 \cdot} \rightarrow \mathrm{CNO}^{-}+\mathrm{MnO}_{2(\mathrm{~s})}
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(b) Balance the following ionic equations by ion-electron method.(x) \mathrm{CN}^{-}+\mathrm{MnO}_{4}^{1 \cdot} \rightarrow \mathrm{CNO}^{-}+\mathrm{MnO}_{2(\mathrm{~s})}

(b) Balance the following equations by oxidation number method(ix) \mathrm{NaCl}+\mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{MnO}_{2} \rightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}+\mathrm{MnSO}_{4}+\mathrm{H}_{2} \mathrm{O}+\mathrm{Cl}_{2}
(b) Balance the following equations by oxidation number method(ix)  \mathrm{NaCl}+\mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{MnO}_{2} \rightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}+\mathrm{MnSO}_{4}+\mathrm{H}_{2} \mathrm{O}+\mathrm{Cl}_{2}
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(b) Balance the following equations by oxidation number method(ix) \mathrm{NaCl}+\mathrm{H}_{2} \mathrm{SO}_{4}+\mathrm{MnO}_{2} \rightarrow \mathrm{Na}_{2} \mathrm{SO}_{4}+\mathrm{MnSO}_{4}+\mathrm{H}_{2} \mathrm{O}+\mathrm{Cl}_{2}

Q.1 Multiple choice questions.(iv) If the salt bridge is not used between two half cells then the voltage.(a) Decrease rapidly(b) Decrease slowly(c) Does not change(d) Drops to zero
Q.1 Multiple choice questions.(iv) If the salt bridge is not used between two half cells then the voltage.(a) Decrease rapidly(b) Decrease slowly(c) Does not change(d) Drops to zero
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Q.1 Multiple choice questions.(iv) If the salt bridge is not used between two half cells then the voltage.(a) Decrease rapidly(b) Decrease slowly(c) Does not change(d) Drops to zero

(b) Balance the following ionic equations by ion-electron method.(v) \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}
(b) Balance the following ionic equations by ion-electron method.(v)  \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}
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(b) Balance the following ionic equations by ion-electron method.(v) \mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}

6. What is electroplating? How steel object can be electroplated with Tin Zinc and Silver?
6. What is electroplating? How steel object can be electroplated with Tin Zinc and Silver?
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6. What is electroplating? How steel object can be electroplated with Tin Zinc and Silver?

MDCAT/ ECAT question bank