NEET UG - Conductance in electrolytic solutions, Kohlrausch's law, electrochemical cells, electrode potentials, Nernst equation, relationship between cell potential and Gibbs energy Online Test (MCQ Quiz)

1. What is the SI unit of conductivity?

A) Ohm meter (Ω·m) B) Siemens per meter (S/m) C) Ohm per meter (Ω/m) D) Siemens meter (S·m)

2. Which of the following factors does NOT affect the conductance of an electrolytic solution?

A) Nature of the electrolyte B) Concentration of the electrolyte C) Temperature of the solution D) Pressure applied to the solution

3. The conductance of a solution is the reciprocal of its:

A) Resistance B) Resistivity C) Conductivity D) Molar conductivity

4. Molar conductivity (Λm) is defined as conductivity (κ) divided by:

A) Molar mass B) Molarity (C) C) Molality (m) D) Density

5. For a strong electrolyte, molar conductivity increases with dilution because:

A) The number of ions increases B) The inter-ionic attraction decreases C) The mobility of ions decreases D) The volume of the solution decreases

6. Kohlrausch's law states that the molar conductivity of an electrolyte at infinite dilution is the sum of the contributions of its:

A) Cations only B) Anions only C) Cations and anions D) Electrons and holes

7. According to Kohlrausch's law, Λm°(NaCl) is equal to:

A) Λm°(Na+) + Λm°(Cl-) B) Λm°(Na+) - Λm°(Cl-) C) Λm°(Na) + Λm°(Cl) D) Λm°(Na+) * Λm°(Cl-)

8. Which of the following expressions correctly represents Kohlrausch's law for an electrolyte A_x B_y?

A) Λm°(A_x B_y) = xΛm°(A^y+) + yΛm°(B^x-) B) Λm°(A_x B_y) = yΛm°(A^x+) + xΛm°(B^y-) C) Λm°(A_x B_y) = xΛm°(A^y-) + yΛm°(B^x+) D) Λm°(A_x B_y) = Λm°(A) + Λm°(B)

9. The limiting molar conductivity of a weak electrolyte can be determined using Kohlrausch's law by extrapolating the plot of Λm versus √C to:

A) Zero concentration B) Infinite concentration C) Zero conductivity D) Infinite conductivity

10. An electrochemical cell converts chemical energy into:

A) Mechanical energy B) Electrical energy C) Thermal energy D) Light energy

11. In an electrochemical cell, oxidation occurs at the:

A) Cathode B) Anode C) Salt bridge D) Electrolyte

12. In an electrochemical cell, reduction occurs at the:

A) Anode B) Cathode C) External circuit D) Electrode surface

13. A galvanic cell is an example of a(n):

A) Electrolytic cell B) Electrochemical cell C) Concentration cell D) Fuel cell

14. An electrolytic cell requires an external source of:

A) Voltage B) Current C) Energy D) Power

15. The electrode potential of a half-cell depends on:

A) Concentration of ions B) Temperature C) Pressure D) All of the above

16. Standard electrode potential (E°) is measured at:

A) 298 K temperature and 1 atm pressure B) 298 K temperature and 1 M concentration C) 298 K temperature, 1 atm pressure, and 1 M concentration D) 0°C temperature and 1 atm pressure

17. The Nernst equation relates the electrode potential (E) to the standard electrode potential (E°) and:

A) Temperature and pressure B) Concentration of reactants and products C) Number of electrons transferred D) All of the above

18. The Nernst equation for a single electrode reaction M^n+ + ne- → M is:

A) E = E° - (RT/nF)ln([M]/[M^n+]) B) E = E° + (RT/nF)ln([M^n+]/[M]) C) E = E° - (nF/RT)ln([M]/[M^n+]) D) E = E° + (nF/RT)ln([M^n+]/[M])

19. At 298 K, the Nernst equation can be simplified to:

A) E = E° - (0.0591/n)log([Products]/[Reactants]) B) E = E° + (0.0591/n)log([Products]/[Reactants]) C) E = E° - (0.0591/n)log([Reactants]/[Products]) D) E = E° + (0.0591/n)log([Reactants]/[Products])

20. If the concentration of product is higher than reactants, the electrode potential will:

A) Increase B) Decrease C) Remain unchanged D) Become zero

21. The cell potential (Ecell) of an electrochemical cell is given by:

A) E_cathode - E_anode B) E_anode - E_cathode C) E_cathode + E_anode D) E_anode / E_cathode

22. The standard cell potential (E°cell) is the difference between:

A) Standard anode potential and standard cathode potential B) Standard cathode potential and standard anode potential C) Standard electrode potentials of both electrodes D) Standard reduction potentials of both electrodes

23. A positive cell potential (Ecell > 0) indicates that the reaction is:

A) Non-spontaneous B) Spontaneous C) At equilibrium D) Reversible

24. The relationship between standard cell potential (E°cell) and standard Gibbs energy change (ΔG°) is given by:

A) ΔG° = -nFE°cell B) ΔG° = nFE°cell C) ΔG° = -nE°cell/F D) ΔG° = nE°cell/F

25. At equilibrium, the cell potential (Ecell) is:

A) Zero B) Infinite C) Equal to E°cell D) Negative

26. The equilibrium constant (K) of a cell reaction is related to the standard cell potential (E°cell) by:

A) E°cell = (RT/nF)ln(K) B) E°cell = -(RT/nF)ln(K) C) E°cell = (nF/RT)ln(K) D) E°cell = -(nF/RT)ln(K)

27. Which of the following statements is true for a spontaneous redox reaction?

A) ΔG° > 0 and E°cell < 0 B) ΔG° < 0 and E°cell > 0 C) ΔG° = 0 and E°cell = 0 D) ΔG° > 0 and E°cell > 0

28. Conductivity (κ) and resistivity (ρ) are related by:

A) κ = 1/ρ B) κ = ρ C) κ = -1/ρ D) κ = 1/√(ρ)

29. Which of the following units is equivalent to S/m?

A) Ω·m B) Ω/m C) mho/m D) mho·m

30. The cell constant (G*) of a conductivity cell is defined as the ratio of:

A) Length (l) to the area of cross-section (A) B) Area of cross-section (A) to the length (l) C) Resistance (R) to resistivity (ρ) D) Conductivity (κ) to conductance (G)

31. Conductance (G) is related to cell constant (G*) and conductivity (κ) by:

A) G = κ * (A/l) B) G = κ / (A/l) C) G = κ * (l/A) D) G = κ / (l/A)

32. Which type of ions have higher molar conductivity at infinite dilution?

A) Larger ions B) Smaller hydrated ions C) Ions with higher charge D) Ions with lower charge

33. Kohlrausch's law is particularly useful for determining the limiting molar conductivity of:

A) Strong electrolytes B) Weak electrolytes C) Metals D) Semiconductors

34. In electrolysis, the electrode connected to the positive terminal of the external battery is called the:

A) Cathode B) Anode C) Electrolyte D) Electrode

35. In electrolysis, the electrode connected to the negative terminal of the external battery is called the:

A) Anode B) Cathode C) Electrode D) Electrolyte

36. Which of the following is a primary example of an electrochemical cell?

A) Electric heater B) Electric motor C) Dry cell battery D) Incandescent bulb

37. Electrode potential is an intensive property, meaning it is independent of:

A) Temperature B) Concentration C) Amount of substance D) Pressure

38. The term 'standard' in standard electrode potential refers to standard conditions of:

A) Temperature only B) Pressure only C) Concentration only D) Temperature, pressure, and concentration

39. The Nernst equation can be used to calculate the electrode potential under non-standard conditions, specifically when:

A) Concentrations are different from 1 M B) Temperature is different from 298 K C) Pressure is different from 1 atm D) Any of the above

40. If the reaction quotient (Q) is greater than the equilibrium constant (K), the reaction will proceed in the:

A) Forward direction B) Reverse direction C) Will be at equilibrium D) Will stop

41. The standard Gibbs energy change (ΔG°) is related to the equilibrium constant (K) by:

A) ΔG° = -RTln(K) B) ΔG° = RTln(K) C) ΔG° = -RT/ln(K) D) ΔG° = RT/ln(K)

42. A negative Gibbs energy change (ΔG < 0) for a cell reaction indicates:

A) The cell reaction is non-spontaneous B) The cell reaction is spontaneous C) The cell reaction is at equilibrium D) The cell reaction requires external energy

43. Faraday's constant (F) represents the charge of:

A) One electron B) One mole of electrons C) One proton D) One mole of protons

44. The molar conductivity of a weak electrolyte approaches a finite value at infinite dilution due to:

A) Complete dissociation B) Partial dissociation C) Inter-ionic attraction D) Solvent effects

45. Which of the following is a typical application of Kohlrausch's law?

A) Calculating cell potential B) Determining solubility product C) Measuring electrode potential D) Predicting reaction spontaneity

46. In a concentration cell, the cell potential arises due to the difference in:

A) Nature of electrodes B) Concentration of the electrolyte C) Temperature D) Pressure

47. For a reversible electrochemical cell reaction, the relationship between cell potential (Ecell) and Gibbs energy change (ΔG) is:

A) ΔG = -nFEcell B) ΔG = nFEcell C) ΔG = -nEcell/F D) ΔG = nEcell/F

48. At 298 K, if E°cell is 0.1 V, the equilibrium constant K for the cell reaction will be approximately:

A) 10^1 B) 10^10 C) 10^20 D) 10^0.1

49. Which of the following statements is INCORRECT regarding electrode potential?

A) It depends on the concentration of ions. B) It depends on temperature. C) It depends on the amount of electrode material. D) It is an intensive property.

Conductance in electrolytic solutions, Kohlrausch's law, electrochemical cells, electrode potentials, Nernst equation, relationship between cell potential and Gibbs energy - Online Test

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