ECAT Pre Engineering Chemistry Chapter 10 MCQ Test With Answer

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

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

The cell which generates electricity as a result of spontaneous oxidation-reduction reaction is called

• Electrolytic cell A
• Nelson's cell B
• Galvanic cell C
• Down's cell D

A half reaction can be defines as :

• It always occurs at cathode. A
• Involves only half of a mole of electrolyte. B
• Occurs at one of the electrode. C
• Goes only half way to completion. 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

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

96500 C of electricity liberates from CuSO₄solution

• 63.5 g of Cu A
• 31.75 g of Cu B
• 96500 g of Cu C
• 100 g of Cu 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

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

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

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

In a compound an atom has negative oxidation state because

• Atom is negatively charged A
• Atom acts as cathode B
• Atom is more electronegative C
• Atom has lowest ionization energy 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 cathodic reaction in the electrolysis of dill H₂SO₄with Pt electrodes

• Reduction A
• Oxidation B
• Both oxidation and reduction C
• neither oxidation or reduction D

Which statement is incorrect about standard hydrogen electrode

• Its oxidation and reduction potential is zero A
• It consists of Pt wire dipped on 1 molar HCI solution B
• The electrolyte is 1 molar NaOH solution C
• H₂gas is passes in it at 1 atmospheric pressure D

Ionization is the process in which ionic compounds when fused or dissolved in water split up into charged particles called :

• Atoms. A
• Electrons. B
• Protons . C
• Ions D

Sodium can be obtained by :

• Electrolysis of acidified water. A
• By heating NaCl and water at 100°
  B
• Electrolysis of molten sodium chloride. C
• Electrolysis of aqueous sodium chloride. D

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

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

During electrolysis, electrons are :

• Lost by anions and gained by cations A
• Gained by anions and lost by cations B
• Gained only C
• Lost only D

Which of the following is a strong electrolyte?

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

The conductivity of strong electrolyte

• Increases on dilution slightly A
• Does not change on dilution B
• Decreases on dilution C
• Depends on density of electrolyte it self D

• Zn A
• H B
• S C
• O 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

Pick out the wrong statement. In electrochemical cell

• Electrons are released at anode A
• Cathode is regarded as negative electrode B
• Chemical energy is converted into electrical energy C
• Salt bridge maintains the electrical neutrality of the solution D

When aqueous solution of NaOH is electrolysed useing graphite electrodes, the product obtained at anode is

• O₂gas A
• H₂gas B
• Na metal C
• Na₂O D

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

Which of the substances Na, Hg, S Pt and graphite can be used as electrodes in electrolytic cells having aqueous solution?

• Na, Pt and graphite A
• Na and Hg B
• Pt and graphite only C
• Na and S only 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

The oxidation number of H is -1 in the compound

• H₂O A
• H₃BO₃ B
• NaOH C
• NaH 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

A dry alkaline cell has porous Zn anode and MnO₂as cathode the electrolyte used is

• Ca(OH)₂ A
• NaOH B
• KOH C
• NH₄OH D