Electrochemistry Test

Electrochemistry

This is electrochemistry Test-05 for CBSE class 12 Chemistry.. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
Al2O3 is reduced by electrolysis at low potentials and high currents. If 4.0 × 104 amperes of current is passed through molten Al2O3 for 6 hours, what mass of aluminium is produced? (Assume 100% current efficiency, atomic mass Al = 27 g/mol)
  • A
    2.4 × $10^5$ g
  • B
    8.1 × $10^4$ g
    Correct
  • C
    1.3 × $10^4$ g
  • D
    9.0 × $10^3$ g
2
The equivalent conductance of M/32 solution of a weak monobasic acid is 8.0 mhos cm2 and at infinite dilution is 400 mhos cm2. The dissociation constant of this acid is
  • A
    6.25 × $10^-4$
  • B
    1.25 × $10^-5$
    Correct
  • C
    1.25 ×$10^-6$
  • D
    1.25 × $10^-4$
3
On the basis of the following E° values, the strongest oxidizing agent is:
Question 3 figure 1
  • A
    $Fe^{3+}$
    Correct
  • B
    $[Fe(CN)_6]^{4–}$
  • C
    $[Fe(CN)_6]^{3–}$
  • D
    $Fe^{2+}$
4
The standard electrode potential is measured by
  • A
    Electrometer
  • B
    Voltmeter
    Correct
  • C
    Galvanometer
  • D
    Pyrometer
5
Aluminum displaces hydrogen from dilute HCl whereas silver does not. The E.M.F. of a cell prepared by combining Al/$Al^+3$ and Ag/Ag+ is 2.46 V. The reduction potential of silver electrode is + 0.80 V. The reduction potential of aluminum electrode is:
  • A
    –3.26 V
  • B
    + 1.66 V
  • C
    –1.66 V
    Correct
  • D
    3.26 V
6
For a cell reaction involving two electrons change, the standard e.m.f. of the cell is found to be 0.295 V at . The equilibrium constant of the reaction at 25°C is
  • A
    2.95 × $10^2$
  • B
    10
  • C
    1 × $10^{-10}$
  • D
    1 × $10^10$
    Correct
7
When KMnO4 acts as an oxidizing agent and ultimately forms $Mn{O_4}^{2–}$, $MnO_2$, $Mn_2O_3$ and $Mn^2+$, then the number of electrons transferred in each case
  • A
    4, 3, 1, 5
  • B
    1, 5, 3, 7
  • C
    3, 5, 7, 1
  • D
    1, 3, 4, 5
    Correct
8
Which of the following is a redox reaction?
  • A
    Mg$(OH)_2$ + 2$NH_4$Cl → MgCl2 + 2$NH_4$OH
  • B
    Zn + 2AgCN → 2Ag + Zn $(CN)_2$
    Correct
  • C
    NaCl + $KNO_3$ → $NaNO_3$ + KCl
  • D
    $CaC_2O_4$ + 2HCl → Ca$Cl_2$ + $H_2C_2O_4$
9
Emf of the cell at 298 K is
Question 9 figure 1
  • A
    0.08 V
    Correct
  • B
    0.06 V
  • C
    0.18 V
  • D
    0.10 V
10
The reversible work done by a galvanic cell is equal to decrease in its Gibbs energy and therefore, if the emf of the cell is E and nF is the amount of charge passed and ΔrG is the Gibbs energy of the reaction, then
  • A
    Option A
    Correct
  • B
    Option B
  • C
    Option C
  • D
    Option D
11
Electrolytic cell is a device for using electrical energy to carry
  • A
    non-spontaneous chemical reactions
    Correct
  • B
    non-spontaneous chemical reactions
  • C
    non-spontaneous chemical reactions
  • D
    spontaneous chemical reactions
12
Resistance of 0.2 M solution of an electrolyte is 50 Ω. The specific conductance of the solution is 1.3 S $m^{–1}$. If resistance of the 0.4 M solution of the same electrolyte is 260 Ω, its molar conductivity is
  • A
    Option A
  • B
    Option B
  • C
    Option C
  • D
    Option D
    Correct
13
Electrochemistry is the study of production of electricity from
  • A
    energy released during spontaneous chemical reactions and the use of electrical energy to bring about non-spontaneous chemical transformations
    Correct
  • B
    nuclear energy and the use of heat energy to bring about non-spontaneous chemical transformations
  • C
    nuclear energy and the use of electrical energy to bring about non-spontaneous chemical transformations
  • D
    energy released during spontaneous chemical reactions and the use of heat energy to bring about non-spontaneous chemical transformations
14
How much electricity in terms of Faraday is required to produce 20.0 g of Ca from molten CaCl2?
  • A
    1.3F
  • B
    0.8F
  • C
    1.2F
  • D
    1F
    Correct
15
For the reduction of silver ions with copper metal the standard cell potential was found to be +0.46V at 25°C. The value of standard Gibbs energy, ΔG° wll be (F = 96500 C $mol^-1$)
  • A
    -98.0 kJ
  • B
    -89.0 kJ
    Correct
  • C
    -44.5 kJ
  • D
    -89.0 J