Electrochemistry  MCQs

MCQs of Electrochemistry

Showing 141 to 150 out of 158 Questions
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141.
What is the maximum work that can be obtained from the cell based on the reaction given below :

Fe(s) + Cu2+(aq) → Fe2+(aq) + Cu(s), E°cell = 0.78 V

What will be the value of Kc for the cell reaction ?

(a) -6.398 × 104 J, 2.918 × 1026
(b) -8.369 × 104 J, 2.95 × 1025
(c) -15.054 × 104 J, 2.246 × 1026
(d) -4.584 × 104 J, 3.824 × 1026
Answer:

Option (c)

142.
When the electrochemical cell represented by, Zn | Zn2+(1 M) || Cu2+(1 M) | Cu , (E°cell = 1.10 V), is completely discharged, what is the value of relative concentrations of Zn2+ and Cu2+ i.e. [Zn2+]Cu2+ ?
(a) Antilog 24.08
(b) 37.2
(c) 1037.2
(d) 9.65 × 104
Answer:

Option (c)

143.
In a fuel cell when methanol is used as the fuel and dioxygen as the oxidizing agent, the following reaction occurs : CH3OHl + 32O2g → CO2g + 2H2Ol

Standard free energy of formation of CH3OH, H2O and CO2 is respectively -166.2, -237.2 and -394.4 kJ mol-1 at 298 K temperature. If standard enthalpy of combustion for methanol is -726 kJ mol-1, calculate the efficiency of the fuel cell. ( Efficiency = ∆G∆H ×100)

(a) 80%
(b) 87%
(c) 90%
(d) 97%
Answer:

Option (d)

144.
Which solution is not filled in salt bridge ?
(a) NH4NO3
(b) KCl
(c) KNO3
(d) Cu(NO3)2
Answer:

Option (d)

145.
Which relation is correct for Faraday's second law of electrolysis ? m1 and m2 = Quantity of product, E1 and E2 = Equivalent weight of product.
(a) m2E2 > m2E1
(b) m1E2 < m2E1
(c) m1E2 = m2E1
(d) m1E2 = m2E2
Answer:

Option (c)

146.
How much quantity of electricity should be passed through aqueous solution of CuSO4 so as to obtain 63.5 gram Cu?( Atomic mass of Cu=63.5 gram mol-1)
(a) 2 faraday
(b) 2 ampere
(c) 2 coulomb
(d) 1 ampere
Answer:

Option (a)

147.
What will be the products obtained at anode and cathode respectively by electrolysis of KHF2 in non-aqueous HF ?
(a) H2 and F2
(b) F2 and H2
(c) O2 and H2
(d) F2 and O2
Answer:

Option (b)

148.
Which of the following formulae is correct for standard cell ?
(a) ΔG = nFEcell
(b) ΔG° = nFEcell
(c) -ΔG° = nFE°cell
(d) ΔG° = nFE°cell
Answer:

Option (c)

149.
Which of the following is the unit of molar conductivity ?
(a) Mho Cm2 gram equ-1
(b) Mho cm2 equ-1
(c) Mho cm2 mole-1
(d) Mho cm2 gram mole-1
Answer:

Option (c)

150.
What is used in the reference calomel cell?
(a) ZnCl2
(b) CuSO4
(c) Hg2Cl2
(d) HgCl2
Answer:

Option (c)

Showing 141 to 150 out of 158 Questions
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