ECAT Pre Engineering Chemistry Chapter 10 MCQ Test With Answer

During redox reaction an oxidizing agent

• Gains electrons A
• Is oxidized B
• Loses electrons C
• Hydrolysed D

Strong reducing agents gave

• Greater positive value of standard reduction potential A
• Greater negative value of standard reduction potential B
• Lesser positive value of standard reaction potential C
• None of these D

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

When aluminium electrode is coupled with copper electrode in a galvanic cell :

• Reduction takes place at aluminium electrode. A
• Oxidation takes place at copper electrode. B
• Reduction takes place at copper electrode. C
• Both (a) and (c) 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

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

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

Cell in which an electric current drives a non-spontaneous reaction is called

• Electrolytic cell A
• Voltaic cell B
• Biological cell C
• Electrochemical cell D

When fused PbBr2 is electrolyzed :

• Lead appears at anode. A
• Lead appears at cathode. B
• Bromine appears at cathode. C
• Lead appears at both electrodes. 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

When electricity is passed through molten electrolyte consisting of alumina and cryolite, 13.5 g of Al are deposited. The number of faradays of electricity passed must be

• 2.0 A
• 1.5 B
• 1.0 C
• 0.5 D

Which one of the following reaction takes place spontaneously

• 
  A
• 
  B
• 
  C
• 
  D

When during electrolysis of a solution of AgNO₃, 9650 coulombs of charge pass through the electroplating bath, the mass of silver deposited on the cathode will be

• 1.08 g A
• 10.8 g B
• 21.6 g C
• 108 g D

The conversion of chemical energy into electrical energy requires :

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

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

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

The galvanic or voltaic cells which are rechargeable called as

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

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

A cell constant is generally found by measuring the conductivity of aqueous solution of

• BaCl₂ A
• KCl B
• NaCl C
• MgCl₂ D

Matals usually conduct electricity because

• There are mobile electrons in the metallic structure A
• Metals are decomposed by current B
• Metals have high resistance C
• In metals the ions are free to move D

The oxidation number of free element is always taken to be

• 0 A
• 1 B
• 2 C
• -1 D

Oxidation number of oxygen in OF₂is

• +1 A
• -1 B
• +2 C
• -2 D

Specific conductivity of a solution

• Increases with dilution A
• Decreases with dilution B
• Remains unchanged with dilution C
• Depends on mass of electrolyte D

Which of the following is a strong electrolyte?

• Ca(NO₃)₂ A
• HCN B
• CH₃COOH C
• NH₄OH D

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

• H⁺

  A

• Na⁺

  B

• OH^-

  C

• Cl^-

  D

In the electrolysis of fused bauxite (Al₂O₃2H₂O) with fused Cryolite (Na₃AlF₆) using carbon rods as anode. The product obtained at cathode is

• Na metal A
• F₂gas B
• Al metal C
• O₂gas 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

Strong oxidizing agents have

• Greater positive value of standard reduction potential A
• Lesser positive value of standard B
• Greater negative value of standard C
• None of these D

An electrolyte

• Forms complex ions solution A
• Gives ions only when electricity is passed B
• Possesses ions even in solid state C
• Gives ions only when dissolved in water D