This document contains a chemistry test on electrochemistry topics including electrodes, electrode potential and measurement, and corrosion prevention. The test has 40 multiple choice questions covering the characteristics and properties of standard hydrogen, calomel, and silver/silver chloride electrodes. It also addresses electrode potential, how it is measured, and factors that influence redox reactions. Additional questions cover corrosion types, the corrosion of iron, and methods for preventing corrosion including alloying, tinning, and galvanization.
PPSC Chemistry Lecturer Preparation (Test # 08)- Malik Xufyan
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PPSC CHEMISTRY CLASS
Test Session
CH: Electrochemistry
Test # 08
For more WhatsApp # 0313-7355727
Topics:
1. Electrodes
2. Electrode potential and its measurement
3. Corrosion and its Prevention
Electrodes
1. Which of the following element act as an inert electrode
A Cu
b) Ag
c) Pt
d) None
2. The composition of a standard hydrogen electrode is
A. hydrogen gas
B. H+ ions
C. platinum electrode
D. all of above
3. Standard hydrogen electrode acts as
a) Primary standard electrode
b) Secondary standard electrode
4. H2 gas in SHE is filled at pressure of
a) 760mm of Hg
b) 750mm of Hg
c) 780mm of Hg
d) 800mm of Hg
5. Potential of SHE is considered as
a) Zero
b) Unity
c) Constant
d) Multiple of 1
6. Calomel electrode is secondary standard electrode, the term calomel means
a) KCl
b) Mercury
c) Mercury chloride paste
d) Choride ion
7. Which of the following is not the characteristics of a calomel electrode?
a) The potential of electrode is not temperature dependent
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b) Preparation of electrode is easy
c) Value of potential or emf is higher for lower concentration of KCl
d) Value of potential decreases with increasing concentration of KCl
8. Which of the following salt bridge solutions must be used for silver/silver chloride
electrode?
a) Saturated KCI
b) Saturated K2SO4
c) Saturated LiCI
d) Saturated KNO3
9. Which of the following is electrode based upon sparingly soluble salts
a) Ag│AgCl (s) , HCl
b) Hg│HgCl2 (s) , KCl
c) Calomel electrode
d) All are correct
10. The mass of a substance which has been produced at an electrode is directly
proportional to the quantity of electricity passed, is
A. Faraday's first law
B. Faraday's second law
C. Faraday's third law
D. Newton's third law
11. The advantage of fuel cell over petrol is its only product
A. oxygen
B. water
C. nitrogen
D. CO2
Electrode Potential and its Measurement
12. Tendency of an electrode to gain or loss of electron is called
a) Electrode
b) Electrical current
c) Electrode potential
d) Oxidation
13. Conventionally, electrode potential refers to
a) Oxidation
b) Reduction
c) Neutralization
d) Charge potential
14. Stronger the oxidizing agent greater is the
A. Oxidation potential
b) Reduction potential
c) Redox potential
d) Emf of the cell
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15. The element that act as anode always have ------ position in electrochemical cell
a) Higher
b) Lower
c) In middle
d) No effect of position
16. The standard electrode potential for any half-cell is the measurement of
A. voltage
B. ions apart
C. radii of ions
D. deposited ions
17. The temperature for the measurement of standard electrode potential is
A. 273 K
B. 300 K
C. 298 K
D. 310 K
18. In an electrolytic cell current flows?
a) From cathode to anode in the outer circuit
b) From anode to cathode outside the cell
c) From cathode to anode inside the cell .
d) Both B & C
19. In an electrochemical cell
a) Potential energy changes into electrical energy
b) Chemical energy changes into electrical energy
c) Kinetic energy decreases
d) Potential energy decrease
20. In which of the following reactions occur at cathode?
a) Cu 2+
+2e-
Cu
b) Cu+2e- Cu2+
c) Hg + 02- HgO
d) Mg + 02 - MgO
21. Electricity in a voltaic cell is produced due to
a) Neutralization
b) Oxidation C.
c) Reduction
d) Both B & C
22. In a redox reaction if the emf is positive then the reaction is
a) Non-spontaneous
b) Spontaneous
c) Both a and b
d) None of these
23. For the measurement of standard electrode potential, Zn is dipped in
a) 1 M ZnO solution
b) 1 M ZnS04 solution
c) 1.5 M ZnS04 solution
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d) 0.1 M ZnSO4 solution
24. In Zn-Cu cell, right half-cell contains -------- electrode
a) Al
b) Zn
c) Cu
d) Fe
25. Zn(s)/Zn+2(aq) 1M ││ Cu+2(aq) 1 M/Cu(s) is representation of reaction in
A. Daniel cell
B. Downs cell
C. Voltaic cell
D. Nelsons cell
26. Calculate the standard cell potential if the standard reduction potential of Cu and
Zn are + 0.34V and -0.76V respectively. The cell is shown below Zn ¦ ZnSO4 ¦¦ CuSO4
¦Cu.
a) 1.10 V
b) 2.20 V
c) 4.30 V
d) 1.50 V
27. EMF of a cell can be calculated as
a) Ecell = Eanode + Ecathode
b) Ecell = Eanode
c) Ecell = Ecathode
d) Ecell = Eanode + 0.01
28. Standard reduction potential of zinc electrode is
a) 0.76
b) -0.76
c) 0.34
d) -0.34
Corrosion and its Prevention
29. What is dry corrosion?
a) Chemical corrosion
b) Physical corrosion
c) Biochemical corrosion
d) Galvanic Corrosion
30. Wet corrosion is also called
a) Dry corrosion
b) Moderate corrosion
c) Electronic corrosion
d) Electrochemical corrosion
31. Chemical formula of rust is
a) Fe2O3. XH2O
b) FeO
c) Fe3O4
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d) Fe2O3
32. Electrochemical corrosion takes place around
a) cathodic area
b) near cathode
c) anodic area
d) near anode
33. Lower is PH , corrosion is
a) Greater
b) Lower
c) Constant
d) None of above
34. Rusting of iron could take place in
a) distilled water
b) ordinary water
c) distilled and ordinary water
d) none of the above
35. Which of the following metals is most active?
a) Magnesium
b) Copper
c) Iron
d) Nickel
36. As compare to iron, aluminum has
a) tendency to oxidize
b) less tendency to oxidize
c) equal tendency to oxidize
d) all of above
37. Corrosion can be prevented by
a) Alloying
b) Tinning
c) Galvanizing
d) all of above
38. The electrolyte used for tin plating is
a) sulphide ore
b) stannous sulphate
c) hydrogen sulphate
d) sodium chloride
39. In tin plating tin acts as
a) Anode
b) Cathode
40. In galvanization or Zn coating, Zn acts as
a) Anode
b) Cathode