ECAT Pre Engineering Chemistry Chapter 10 MCQ Test With Answer

The oxidation number of chromium in K₂Cr₂O₇is

• 14 A
• 12 B
• 6 C
• None of these 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

Caustic soda is obtained by electrolysis of conc. aqueous solution of NaCI in a cell called

• Daniell's cell A
• Nelson's cell B
• Down's cell C
• Voltaic cell D

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

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

2.5 faradays of electricity is passed through solution of CuSO_{4. The number of gram equivalents of copper deposited on the cathode would be}

• 1 A
• 2 B
• 2.5 C
• 1.25 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

When a metal is dipped in 1 molar of its solution at 298 K. then potential set up is called

• Standard electrode potential A
• Electric charge B
• Ionization potential C
• Electroplating 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

The process of electrical coating of one metal on another to protect, decorate or to have greater resistance to corrosion is called

• Electroplating A
• Electrolysis B
• Conduction C
• Induction D

The standard EMF of Daniel cell is 1.10 volt. The maximum electrical work obtained from the Daniel cell is

• 212.3 kJ A
• 175.4 kJ B
• 106.15 kJ C
• 53.07 kJ D

Corrosion is basically a

• Altered reaction in presence of H₂O A
• Electrochemical phenomenon B
• Interaction C
• Union between two light metals and a heavy metal D

The cell in which a non-spontaneous redox reaction takes place as a result electricity is known as :

• Electrolytic cell. A
• Voltaic cell. B
• Daniel cell. C
• Dry cell. D

The unit of specific conductivity is

• Ohm cm^-1 A
• Ohm cm^-2 B
• Ohm^-1cm C
• Ohm^-1cm^-1 D

When fused PbBr₂is electrolyzed

• Bromine appears at he cathode A
• Lead is deposited at the cathode B
• Lead appears at the anode C
• None of these happens D

Alkaline battery has a voltage of

• 4.5 V A
• 3.5 V B
• 2.5 V C
• 1.5 V D

In an electrolytic cell, the electrons flow from :

• Cathode to anode or opposite A
• Cathode to anode B
• Anode to cathode C
• Random flow D

The substance having highest conductivity at room temperature among the following is

• 0.1 N HCl A
• 0.1 N NaCl
  B
• Graphite C
• Glass D

The electrolysis of CuSO₄aqueous solution using copper as cathode as well an anode the substance which deposits at cathode is

• H₂SO₄ A
• Oxygen B
• Copper C
• Hydrogen D

Lead accumulator contains

• 30% NaCI solution as electrolyte A
• 30% HCI solution as electrolyte B
• 30% H₂SO₄solution as electrolyte C
• 30% NaOH solution as electrolyte D

Best way to prevent rusting of iron is by

• Making iron cathode A
• Putting it in saline water B
• Both of these C
• None of these D

When quantity of electricity passed is one faraday then the mass deposited at the electrode is equal to

• One gm, atomic weight A
• One gm, Equivalent B
• Eletrochemical equivalent C
• None of the above D

Li has the lowest reduction potential while the element with highest reduction potential is

• H A
• F B
• O C
• N D

• Fe is reduced A
• Fe is oxidized B
• Cl₂is oxidized C
• None of these D

Same amount of electric current is passed through solutions of AgNO₃and HCl. If 1.08 g of silver is obtained in the first case, the amount of hydrogen liberated as S.T.P in the second case is

• 112 cm³ A
• 22400 cm³ B
• 224 cm³ C
• 1.008 g D

The voltaic or galvanic cells which cannot be recharged are called

• Primary cells A
• Secondary cells B
• Infinite cells C
• Fuel cells D

Most metals are conductors of electricity because of the :

• Light weight. A
• Immobility of the electrons. B
• Lustrous surfaces C
• Relatively free movement of their electrons 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

In the electrolysis of aqueous solution of sodium nitrate, the ions which are reduced at the cathode are

• H₃O⁺ A
• Na⁺ B
• OH^- C
• NO^3- D

Which one of the following reaction takes place spontaneously

• 
  A
• 
  B
• 
  C
• 
  D

Electrolytes in the form of solution or in the fused state have the ability to conduct :

• Light. A
• Electricity. B
• Ions. C
• Electrons. D