PPSC Chemistry Lecturer Preparation (Test # 08)- Malik Xufyan
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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.
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PPSC Chemistry Lecturer Preparation (Test # 08)- Malik Xufyan
- 1. Malik Xufyan WhatsApp # 0313-7355727 1 | P a g e 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
- 2. Malik Xufyan WhatsApp # 0313-7355727 2 | P a g e 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) AgâAgCl (s) , HCl b) HgâHgCl2 (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
- 3. Malik Xufyan WhatsApp # 0313-7355727 3 | P a g e 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- ï Cu b) Cu+2e- ï Cu2+ c) Hg + 02- ï HgO d) Mg + 02 - ï 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
- 4. Malik Xufyan WhatsApp # 0313-7355727 4 | P a g e 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 ââ 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 Š ZnSO4 ŠŠ CuSO4 ŠCu. 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
- 5. Malik Xufyan WhatsApp # 0313-7355727 5 | P a g e 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