New ! Chemistry MCQ Practise Tests

12th Standard Chemistry Electro Chemistry English Medium Free Online Test One Mark Questions 2020 - 2021

12th Standard

    Reg.No. :
  •  
  •  
  •  
  •  
  •  
  •  

Chemistry

Time : 00:20:00 Hrs
Total Marks : 20

    Answer all the questions

    20 x 1 = 20
  1. The number of electrons that have a total charge of 9650 coulombs is

    (a)

    6.22 ×1023

    (b)

    6.022 ×1024

    (c)

    6.022 ×1022

    (d)

    6.022 ×10−34

  2. The button cell used is watches function as follows
    Zn (s) + Ag2O (s) + H2O (l) ⇌ 2Ag (s) + Zn2+ (aq) + 2OH-(aq)the half cell potentials
    are Ag2 O (s) + H2O (l) + 2e- →2Ag (s) + 2OH- (aq) Eo.34V The cell potential will be

    (a)

    0.84V

    (b)

    1.34V

    (c)

    1.10V

    (d)

    0.42V

  3. Electrolyte KCl KNO3 HCl NaOAC NaCl
    Λ-
    (Scm2 mol-1)
    149.9 145.0 426.2 91.0 126.5

    Calculate ΛoHoAC using appropriate molar conductances of the electrolytes listed above at infinite dilution in water at 25oC.

    (a)

    517.2

    (b)

    552.7

    (c)

    390.7

    (d)

    217.5

  4. How many faradays of electricity are required for the following reaction to occur MnO→ Mn 4-

    (a)

    5F

    (b)

    3F

    (c)

    1F

    (d)

    7F

  5. During electrolysis of molten sodium chloride, the time required to produce 0.1mol of chlorine gas using a current of 3A is

    (a)

    55 minutes

    (b)

    107.2 minutes

    (c)

    220 minutes

    (d)

    330 minutes

  6. Among the following cells
    I) Leclanche cell
    II) Nickel – Cadmium cell
    III) Lead storage battery
    IV) Mercury cell
    Primary cells are

    (a)

    I and IV

    (b)

    I and III

    (c)

    III and IV

    (d)

    II and III

  7. The equivalent conductance of M/36solution of a weak monobasic acid is 6mho cm2 and at infinite dilution is 400 mho cm2. The dissociation constant of this acid is

    (a)

    1.25 ×10−6

    (b)

    6.25 x 10-6

    (c)

    1.25 ×10−4

    (d)

    6.25 x 10 -5

  8. A certain current liberated 0.504gm of hydrogen in 2 hours. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution

    (a)

    31.75

    (b)

    15.8

    (c)

    7.5

    (d)

    36.5

  9. Which one of the following solution has highest equivalent conductance?

    (a)

    0.1 M NaCI

    (b)

    0.05 M NaCI

    (c)

    0.005 M NaCI

    (d)

    0.25 M NaCI

  10. Which among the following is the strongest reducing agent?

    (a)

    F2

    (b)

    Cl2

    (c)

    Zn

    (d)

    Li

  11. A device in which spontaneous chemical reaction generates electric current.

    (a)

    Galvanic cell

    (b)

    Voltaic cell

    (c)

    Daniel cell

    (d)

    All the above

  12. The limiting molar conductivities of HCI, CH3COONa and NaCI are respectively 425, 190 and 150 mho cm2 mol-1 at 25°C. The molar conductivity of 0.1 M acetic acid is 9.2 mho cm2 mol-1. The degree of dissociation of 0.1 Macetic acid is

    (a)

    0.10

    (b)

    0.02

    (c)

    0.19

    (d)

    0.03

  13. Recharging of lead storage battery involves

    (a)

    anode is reduced to pb

    (b)

    cathode is reduced to pb

    (c)

    cathode is oxidised to pb

    (d)

    anode is oxidised to pbO2

  14. What happens during the electrolysis of molten sodium chloride?

    (a)

    Cl2 is released at the cathode

    (b)

    Liquid sodium is obtained at the anode

    (c)

    The emf of the overall reaction is -4.07 V

    (d)

    Cl2 is released at the cathode and Liquid sodium is obtained at the anode

  15. When one coulomb of electricity is passed through an electrolytic solution the mass deposited on the electrode is equal to

    (a)

    equivalent weight

    (b)

    molecular weight

    (c)

    electrochemical equivalent

    (d)

    one gram

  16. The specific conductance of a 0.01 M solution of KCI is 0.0014 ohm-1 em-1 at 25°C. Its equivalent conductance is

    (a)

    14 ohm-1 cm2eq-1

    (b)

    140 ohm-1 cm2eq-1

    (c)

    1.4 ohm-1 cm2eq-1

    (d)

    0.14 ohm-1 cm2eq-1

  17. The equivalent conductivity of CH3COOH at 25°C is 80 ohm-1 cm2 eq-1 and at infmite dilution 400 ohm-1 cm-1 eq-1. The degree of dissociation of CH3COOH is

    (a)

    1

    (b)

    0.2

    (c)

    0.1

    (d)

    0.3

  18. λc = μc for,

    (a)

    NaCI

    (b)

    H2SO4

    (c)

    Na2SO4

    (d)

    Al2(SO4)3

  19. The inert electrode is __________

    (a)

    Cu

    (b)

    Pt

    (c)

    Zn

    (d)

    None of these

  20. The gas that bubbles over the platinum electrode in SHE is __________

    (a)

    hydrogen

    (b)

    helium

    (c)

    neon

    (d)

    oxygen

*****************************************

TN 12th Standard Chemistry free Online practice tests

Reviews & Comments about 12th Standard Chemistry Electro Chemistry English Medium Free Online Test One Mark Questions 2020 - 2021

Write your Comment