ECAT Pre Engineering Chemistry Chapter 10 MCQ Test With Answer

An electric current is passed through silver nitrate solution using silver electrodes.10.79 g of silver was found to be deposited on the cathode if the same amount of electricity is passed through copper sulphate solution using copper electrodes, the weight of copper deposited on the cathode is

• 6.4 g A
• 2.3 g B
• 128.8 g C
• 3.2 g 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

The function of salt bridge is :

• To increase movement onions. A
• To increase the emf of cell. B
• To decrease the temperate C
• To maintain electrical neutrality D

The reaction is galvanic cell is

• Spontaneous A
• Non-spontaneous B
• Acid-base C
• None of these 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

A cell in which spontaneous redox reaction generates an electric current is called

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

• Iodine can oxidise iron A
• Bromine can oxidise iron B
• Iodine can oxidise bromine C
• Iron can oxidise bromine 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

In a solution of CuSO₄how much time will be required to precipitate 2g copper by 0.5 ampere current?

• 12157.48 sec A
• 102 sec B
• 510 sec C
• 642 sec D

A smuggler could not carry gold by chemically depositing iron on the gold surface since

• Gold is denser A
• Iron rusts B
• Gold has higher reduction potential then iron C
• Gold has lower reduction potential then iron D

The function of salt bridge in the galvanic or voltaic cell is to

• Carry out oxidation at anode A
• To carry out reduction at cathode B
• Carry out electrolysis C
• To prevent the net charge accumulation in either of the half cells D

Prevention of corrosion of iron by Zn coating is called

• Galvanization A
• Cathodic protection B
• Electrolysis C
• Photoelectrolysis 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

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

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

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

Which of the following correctly describes the process occurring at the electrodes when molten NaCl is electrolyzed:

• No reaction at anode, reduction at cathode. A
• No reaction at cathode, oxidation at anode. B
• Oxidation at anodes, reduction at cathode. C
• Oxidation at cathode, reduction at anode. D

What will be the weight of deposited silver on passing 965 coulombs of electricity in solution of AgNO₃?

• 1.08 g A
• 2.16 g B
• 0.54 g C
• 0.27 g 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

Alkaline battery has a voltage of

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

Coinage metals like Au, Pt, Ag and Cu are the least reactive metals and don't liberate H₂gas when treated with acids because

• These have very high positive values of reduction potentials A
• These have very high negative values of reduction potentials B
• Their ionization potentials are lowest C
• Their reduction potentials are close to SHE D

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

While balancing an equation by ion electron method, the number of oxygen atoms are balanced by

• OH^- A
• H₂O B
• O₂ C
• H⁺ 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 standard e.m.f. of a galvanic cell involving cell reaction with n = 2 is found to be 0.2965 V at 25°C. The equilibrium constant of the reaction would be

• 1.0 x 10¹⁰ A
• 2.0 x 10¹¹ B
• 4.0 x 10¹² C
• 1.0 x 10² D

Which of the following will be good conductor of electricity

• Pure distilled water A
• Molten NaCl B
• Dilute solution of glucose C
• Chloroform 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

Pure water does not conduct electricity because it

• Has low boiling point A
• Is almost unionized B
• Is neutral C
• Is readily decomposed D

In the presence of copper electrodes the electrolysis of aqueous CuSO₄produces at cathode

• H₂gas A
• O₂gas B
• SO₂gas C
• Cu metal 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

Time required to deposit one millimole of aluminium metal by the passage of 9.65 amperes through molten electrolyte containing aluminium ion is

• 30 s A
• 10 s B
• 30,000 s C
• 10,000 s D