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Chapter No.7 - Electrochemistry
MCQs And Fill In The Blanks
Text Book Exercise
SECTION- A: MULTIPLE CHOICE QUESTIONSTick Mark (✓) the correct answer
1. Alloy of Cu - Sn is called
(a) Brass
(b) Bronze
(c) Monel
(d) Bell metal ✓
2. Which one is Alloy.
(a) Graphite
(b) Mercury
(c) Steel ✓
(d) Water
3. Value of 1 Faraday is equal to:
(a) 9.65 C
(b) 9650 C
(c) 96500 C ✓
(d) 965 C
4. Which one is non electrolyte.
(a) Aqueous HCl
(b) Aqueous NaCl
(c) Molten KCl
(d) Urea ✓
5. Which one is oxidizing agent.
(a) Al
(b) H2S
(c) Cl2 ✓
(d) NaH
6. Which one is reducing agent.
(a) H2S04
(b) HNO3
(c) Al ✓
(d) I2
7. Which one forms weak electrolyte solution with water:
(a) HCl
(b) KOH
(c) NaCl
(d) CH3COOH ✓
8. In Daniel cell ____ is used as cathode.
(a) Zn
(b) Cu ✓
(c) Sn
(d) Pb
9. 1 g equivalent weight of Al is equal to:
(a) 9 g ✓
(b) 27 g
(c) 54 g
(d) 1 g
10. Which one is correct statement.
(a) Oxidation occurs at cathode.
(b) Reduction occurs at anode
(c) Reduction occurs at cathode ✓
(d) Ions lose electrons at cathode.
11. Electrochemistry deals with the conversion of:
(a) electrical energy into chemical energy
(b) chemical energy into electrical energy
(c) Both of 'a' and 'b' ✓
(d) None of them
12. From a chemical substance, oxidation may involve:
(a) introduction of oxygen
(b) removal of hydrogen
(c) Both 'a' & 'b' ✓
(d) None of these
13. From a chemical substance, reduction may involve:
(a) removal of oxygen
(b) addition of oxygen
(c) removal of hydrogen
(d) All of them ✓
14. The electrochemical reaction in which atom, molecule or ion loses electrons is called:
(a) reduction reaction
(b) oxidation reaction ✓
(c) electrolytic reaction
(d) cathodic reaction
15. In oxidation reaction, oxidation number:
(a) becomes zero
(b) remains the same
(c) decreases
(d) increases ✓
16. The electrochemical reaction in which atom, molecule or ion accepts electron is called:
(a) reduction reaction ✓
(b) oxidation reaction
(c) electrolytic reaction
(d) cathodic reaction
17. In reduction reaction, oxidation number:
(a) becomes zero
(b) remains the same
(c) decreases ✓
(d) increases
18. Which one of these is a reducing agent?
(a) Cl2
(b) KMnO4
(c) H2SO4
(d) Zn ✓
19. Which one of these is NOT a reducing agent?
(a) Zn
(b) HNO3 ✓
(c) Al
(d) KH
20. The reaction occurs at each electrode is called:
(a) zero cell reaction
(b) quarter cell reaction
(c) half cell reaction ✓
(d) full cell reaction
21. Types of electrochemical cells are:
(a) two ✓
(b) three
(c) four
(d) five
22. Which of the following is a strong electrolyte?
(a) H2CO3
(b) NH4OH (c) AgCl
(d) NaCl ✓
23. Which of the following is NOT an electrolyte?
(a) Benzene
(b) Glucose
(c) Both of 'a' & 'b' ✓
(d) None of these
24. The substance used for electrolysis is called:
(a) electrolyte ✓
(b) cell
(c) electricity
(d) None of them
25. The device that converts chemical energy into electrical energy or electrical energy into chemical energy is called:
(a) electrochemical cell ✓
(c) photocell
(b) electrolytic cell
(d) pencil cell
26. In which type of cells, oxidation (loss of electrons) occurs at anode and reduction (gain of electrons) occurs at the cathode?
(a) Electrochemical
(b) Electrolytic ✓
(c) Primary
(d) Secondary
27. Faraday's First Law of Electrolysis states that the amount of any substance that is deposited or liberated at an electrode during electrolysis is directly proportional to the:
(a) charge deposited on electrodes
(b) mass of the substance or electrolyte
(c) their chemical equivalent masses
(d) quantity of electricity passed through the electrolyte ✓
28. Coulomb (C) = ____:
(a) Ampere (A) + time (t)
(b) Ampere (A) - time (t)
(c) Ampere (A) x time (t) ✓
(d) Ampere (A) ÷ time (t)
29. The mass of the substance liberated or deposited per unit charge that passes is called:
(a) electrochemical equivalent ✓
(b) mass equivalent
(c) physio-chemical equivalent
(d) volume equivalent
30. Equivalent mass = ____:
(a) Atomic mass x Valency
(b) Atomic mass / Valency ✓
(c) Atomic mass + Valency
(d) Atomic mass x (Valency)2
31. According to Faraday's Second Law of Electrolysis, the amount of different substances deposited or liberated due to passage of the same quantity of current through different electrolysis are proportional to:
(a) charge deposited on electrodes
(b) mass of the substance or electrolyte
(c) their chemical equivalent masses ✓
(d) quantity of electricity passed through the electrolyte
32. Quantity of charge which deposits or liberates 1 gm equivalent weight of a substance is called:
(a) 1 Farad
(b) 1 Ampere
(c) 1 Coulomb
(d) 1 Faraday ✓
33. Dry cell is also called:
(a) Leclanche cell ✓
(b) secondary battery
(c) lead storage battery
(d) None of these
34. Dry cell uses:
(a) manganese dioxide as anode & zinc as cathode
(b) zinc as anode & manganese dioxide as cathode ✓
(c) lead as anode & lead oxide as cathode
(d) lead oxide as anode & lead as cathode
35. In a dry cell, this is used as an electrolyte.
(a) NH4Cl paste
(b) ZnCl2 paste
(c) either 'a' or 'b' ✓
(d) Both 'a' & 'b'
36. Lead storage battery is an example of:
(a) Leclanche cell
(b) secondary battery ✓
(c) primary battery
(d) None of them
37. Lead storage battery uses:
(a) manganese dioxide as anode & zinc as cathode
(b) zinc as anode & manganese dioxide as cathode
(c) lead as anode & lead oxide as cathode ✓
(d) lead oxide as anode & lead as cathode
38. In lead storage battery, this is used as electrolyte.
(a) NH4Cl paste
(b) ZnCl2 paste
(c) solution of H2SO4 ✓
(d) None of these
39. Number of alloys, used for different purposes, are:
(a) 70
(b) 700
(c) 7000 ✓
(d) 70000
40. Brass is an alloy of:
(a) Cu-Zn ✓
(b) Cu-Sn
(c) Cu-Zn-Sn
(d) Ag-Cu
41. Alloy of iron and carbon is called:
(a) Brass
(b) Bronze
(c) Duralumin
(d) Steel ✓
42. It is called 100% pure gold.
(a) 24 karat ✓
(b) 22 karat
(c) 18 karat
(d) 10 karat
43. To make stainless steel, iron is mixed with:
(a) Cu Zn
(b) Cu-Sn
(c) Cr-Ni ✓
(d) Ag-Cu
44. The coating of metal at the surface of other metal by the electrolytic process is called:
(a) electrolysis
(b) electrolyte
(c) galvanizing
(d) electroplating ✓
45. The process in which zinc is electrolytically coated at the surface of other base metal is called:
(a) electrolysis
(b) electrolyte
(c) galvanizing ✓
(d) electroplating
46. In W = ZAt, 'Z' is called:
(a) constant
(b) product
(c) electrochemical equivalent ✓
(d) None of them
FILL IN THE BLANKS:
- Oxidation is the loss of electron by chemical substance.
- Reduction is the gain of electron by chemical substance.
- An electrolyte consists of free moving ions and conduct electricity.
- An electrode is an electrical conductor.
- The electrode at which oxidation occurs is called anode.
- The electrode at which reduction occurs is called cathode.
- Electrolysis is a process of migration of ions towards cathode and anode when current passes through en electrolyte.
- Oxidizing agent helps in oxidation by accepting electrons.
- Reducing agent helps in reduction by losing electrons.
- A galvanic cell converts chemical energy into electrical energy.
- An electrolytic cell uses electrical energy to derive a non spontaneous reaction.
- Corrosion of iron is called rusting.
- Corrosion of metal can be prevented by alloying, paint or electroplating metal by zinc, tin, silver, chromium etc.
- An alloy is a mixture of metal with metal or metal with non metal.
- Digital watches, calculators, cars and mobile phones. powered by batteries or dry cells.
- 24 karat gold is called 100% pure gold.
- The formula of rust is (iron (III) oxide) (Fe2O3.nH2O)
CONCEPT MAP
Point To Remember:
Reaction: Oxidation reaction- Status: Loss of Electron
- Electrode: Anode (positive electrode)
- Ion on Anode: Anion
- Agent: Reducing agent (Cation)
Reaction: Reduction reaction
- Status: Gain of Electron
- Electrode: Cathode (negative electrode)
- Ion on Cathode: Cation
- Agent: Oxidizing agent (Anion)
Some Important Alloys With Their Components And Applications
Name Of Alloy | Components | Applications |
---|---|---|
Bell Metal | Cu-Sn | Casting of bell |
Brass | Cu-Zn | Door nobs and hand rails due to antibacterial nature, Hose nozzles, Stamping dies. |
Bronze | Cu-Zn-Sn | Coins, medals, tools, etc. |
Monel | Ni-Cu-Fe | Corrosion resistant containers |
Duralumin | Al-Cu-Mg-Ni | Boat, Aircraft etc. |
Solder | Sn-Pb-Cu-Sb | Joining electrical components into circuits |
Alnico | Fe-Al-Ni-Co | Magnets used in loud speakers |
Amalgam | Hg-Ag-Cu-Zn | Dental filling |
Cupronickel | Cu-Ni-Mn | Coins |
Pewter | Sn-Cu-Pb-Sb-Bi | Ornaments |
Sterling silver | Ag-Cu | Cutlery set, Medical tools |
White Gold (18 Karat) | Au-Pb-Ag-Cu | Jewelry |
Red Gold (18 K) | Au-Cu | Jewelry |
Yellow Gold (22 K) | Au-Ag-Cu-Zn | Jewelry |
Elements Use In Alloys with Their Symbols:
- Ag = Silver (Argentum)
- Al = Aluminium
- Au = Gold (Aurum)
- Bi = Bismuth
- Co = Cobalt
- Cu = Copper
- Fe = Iron (Ferrum)
- Hg = Mercury (Hydragyrum)
- Mg = Magnesium
- Mn = Manganese
- Ni = Nickel
- Pb = Lead (Plumbum)
- Sb = Antimony (Stibium)
- Sn = Tin (Stannum)
- Zn = Zinc
Correction of 1. Bell metal
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