Page 181 - Chemistry ICSE Class X

Electrolysis 167
18. An electrolytic cell is set up using two platinum electrodes and an aqueous solution of copper(II) sulphate.

(a) Draw the labelled diagram of the electrolytic cell.
(b) Name the ions present in the cell.
(c) Name the ions migrating towards anode.
(d) Name the ions migrating towards cathode.
(e) Name the ions which will not be discharged at the electrodes during electrolysis.
(f) Write the reaction at cathode.
(g) Write the reaction at anode.
(h) Name the spectator ion in the solution.

19. (a) Which of the Zn and Cu would occur more readily in nature as metal and which as ion?
(b) Why cannot we store AgNO solution in a copper vessel?
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(c) Out of Cu and Ag, which is more active?

Questions from Board Papers

Q 1. Select the correct answer from the choices A, B, C and D which are given. [ICSE 2010]
(i) A compound which liberates reddish-brown gas around the anode during electrolysis in its molten state is:
(A) Sodium chloride (B) Copper(II) oxide
(C) Copper(Il) sulphate (D) Lead(II) bromide
(ii) Identify the weak electrolyte from the following: [ICSE 2012]
(A) Sodium Chloride solution (B) Dilute Hydrochloric acid
(C) Dilute Sulphuric acid (D) Aqueous acetic acid
Q 2. Mr. Ramu wants to electroplate his key-chain with nickel to prevent rusting. For this electroplating: [ICSE 2010]
(i) Name the electrolyte (ii) Name the cathode
(iii) Name the anode (iv) Give reaction at the cathode
(v) Give reaction at the anode.
Q 3. Three different electrolytic cells A, B, C are connected in separate circuits. Electrolytic cell A contains sodium
chloride solution. When the circuit is completed, a bulb in the circuit glows brightly. Electrolytic cell B contains
acetic acid solution and in this case the bulb in the circuit glows dimly. The electrolytic cell C contains sugar
solution and the bulb does not glow. Give a reason for each of these observations. [ICSE 2010]
Q 4. Give reasons as to why the electrolysis of acidulated water is considered to be an example of catalysis. [ICSE 2011]
Q 5. During the electrolysis of copper (II) sulphate solution using platinum as cathode and carbon as anode:
(i) What do you observe at the cathode and at the anode ?
(ii) What change is noticed in the electrolyte ?
(iii) Write the reactions at the cathode and at the anode. [ICSE 2011]
Q 6. Some word/words are missing in the following statement. You are required to rewrite the statement in the
correct form using the appropriate word/words: [ICSE 2012]
(i) Cations migrate during electrolysis.
Q 7. Give reason, why an aqueous solution of sodium chloride conducts electricity. [ICSE 2012]
Q 8. Select the correct answer from the list given in brackets: [ICSE 2012]
(i) An aqueous electrolyte consists of the ions mentioned in the list, the ion which could be discharged most
2+
+
2+
2+
readily during electrolysis. [Fe , Cu , Pb , H ].
(ii) The metallic electrode which does not take part in an electrolytic reaction. [Cu, Ag, Pt, Ni].
(iii) The ion which is discharged at the anode during the electrolysis of copper sulphate solutions using copper
+
2–
2+
–
electrodes as anode and cathode. [Cu , OH , SO , H ].
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