ECAT Chemistry Chapter 10 Electrochemistry

K,Ca and Li metals may be arranged in decreasing order of their reduction potential as :

• Li, k, Ca A
• Ca, K, Li B
• Li, Ca, K C
• K, Ca, Li D

96500 C electricity is passed through CuSO₄. The amount of copper precipitated is

• 0.25 mole A
• 0.5 mole B
• 1.0 mole C
• 2.00 mole D

Standard reduction electrode potential of three metals A, B and C are erespectively + 0.05 V, -3.0 and -1.2V. The reducting power of

• B > C > A A
• A > B > C B
• C > B > A C
• A > C > B D

What are the products electrolysis of aqueous sodium chloride at two electrodes

• Chlorine at anode and oxygen at cathode. A
• Hydrogen at anode and chlorine at cathode. B
• Chlorine at anode and hydrogen at cathode. C
• Chlorine at anode and sodium at cathode. D

The reduction potential to copper electrode is +0.34 V and that of Zn electrode is -0.76 V. when these two are coupled the e.m.f. of the cell is

• -0.42 V A
• +0.42 B
• -1.10 V C
• +1.10 V D

The equivalent conductivity of 0.1 M week acid is 100 times less than at infinite dilution. The degree of dissociation is

• 100 A
• 10 B
• 0.01 C
• 0.001 D

Metals like Fe, Mg, Al, Cr, Zn have more negative reduction potentials that is whey

• These don't react with steam A
• These react very slowly with steam to liberate H₂gas B
• These react rapidly with steam to produce the metallic oxides and liberate H₂gas C
• These react with cold water violently D

When electric current is used to carry out non-spontaneous redox, the process is called

• Hydrolysis A
• Electrolysis B
• Decomposition C
• Neutralization D

Which statement is incorrect for NICAD battery

• The electrolyte is alkali A
• Cd acts as anode B
• MnO₂acts as electrolyte C
• NiO₂acts as cathode D

The amount of electricity that can deposit 108 g of silver from silver nitrate solution is

• 1 ampere A
• 1 coulomb B
• 1 faraday C
• 2 ampere D

When aqueous NaCl is electrolyzed, which of the following ions get discharged at anode :

• H⁺

  A

• Na⁺

  B

• OH^-

  C

• Cl^-

  D

An electric current is passed through silver voltameter connected to a water voltmeter. The cathode of the silver voltameter is 0.108 g more at the end of the electrolysis. The volume of oxygen evolved at STP is

• 56 cm³ A
• 550 cm³ B
• 5.6 cm³ C
• 11.2 cm³ D

F₂, Cl₂, Br₂and l₂lie below SHE is the Electro chemical series that is why these

• Undergo reduction A
• Undergo oxidation B
• Liberate H₂gas with steam C
• None of these D

Purification of an impure copper is made by electrolytic cell, in which impure copper is anode and pure copper is cathode, and the electrolyte used is

• H₂SO₄ A
• CuSO₄ B
• ZnSO₄ C
• Na₂SO₄ D

A current of 9.65 ampere flowing for 10 minutes deposits 3.0 g of the metal which is monovalent. The atomic mass of the metal is

• 10 A
• 50 B
• 30 C
• 96.5 D

Which of the following cannot conduct electricity :

• NaCl fused. A
• NaCl(aq)
  B
• NaCl(Solid)
  C
• Both (b) and (c) D

A solution of sodium sulphate was electrolysed using some insert electrodes. The products at the electrodes are

• O₂, H₂ A
• O₂, Na B
• O₂, SO₂ C
• O₂, S₂O₈² D

In a Galvanic cell

• Chemical energy is converted into electricity A
• Chemical energy is converted into heat B
• Electrical energy is converted into heat C
• Electrical energy is converted into chemical energy D

Calculate the amount of charge flowing in 2 minute in a wire of resistance 10Ωwhen a potential difference of 20 V is applied

• 120 C A
• 240 C B
• 20 C C
• 4 C D

• A strong reducing agent A
• A strong oxidising agent B
• Better oxidising agent than hydrogen C
• Less reducing agent than hydrogen D

Reduction or oxidation potential of standard hydrogen electrode is :

• 0.0 Volt A
• 0.8Volt B
• 1.0Volt C
• 1.8Volt D

In electrolysis of NaCl when Pt electrode is taken then H₂is liberated at cathode while with Hg cathode it forms sodium amalgam

• Hg is more inert than Pt A
• More voltage is required to deduce H⁺at Hg than Pt B
• Na is dissolved in Hg while it does not dissolve in Pt C
• Conc. of H⁺ions is larger when Pt electrode is taken D

If the salt bridge is not used between two half cells, then the voltage

• Decrease rapidly A
• Decrease slowly B
• Does not change C
• Drops to zero D

Electrochemistry is concerned with the conversion of electrical energy into chemical energy in :

• Galvanic cell A
• Electrolytic cell B
• Voltaic cell C
• Both (a) and (c) D

In electrolytic cells, the chemical changes may be :

• Either spontaneous or non-spontaneous A
• Always spontaneous B
• Always non-spontaneous C
• More spontaneous and less non-spontaneous. D

In a hydrogen-oxygen fuel cell, combustion of hydrogen occurs to

• Generate heat A
• Remove adsorbed oxygen from electrode surfaces B
• Produce High purity water C
• Create potential difference between two electrodes D

Metallic conduction is also called as :

• Ionic conduction. A
• Protonic conduction. B
• Electronic conduction C
• Super conduction D

When electrically is passed through molten Al₂O₃+ Na₃AlF₆and 13.5 gms of Al are deposited, the number of farady must be

• 0.5 A
• 1.0 B
• 1.5 C
• 2.0 D

• Adding H₂O and H⁺ions A
• Adding OH^-ions B
• Adding O²molecules C
• Adding O atoms D

The value of SHE is cathode and anode is always taken to be

• One A
• Zero B
• Different C
• Same D