ECAT Pre Engineering Chemistry Chapter 10 MCQ Test With Answer

Which one of the following reactions is not spontaneous

• 
  A
• 
  B
• 
  C
• 
  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

Sodium metal is obtained by the electrolysis of fused NaCl in cell is called

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

The conversion of chemical energy into electrical energy requires :

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

The oxidation number of chromium in K₂Cr₂O₇is

• 14 A
• 12 B
• 6 C
• None of these D

The reaction is galvanic cell is

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

Standard reduction of Zn = -0.76 V and that of Ni is -0.25 V. On coupling them by a salt bridge which of these will act as anode

• Salt bridge will act as anode A
• Zn will act as anode B
• Ni will act as anode C
• None of these 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

Which of the following (1 M) conducts more electricity?

• Sulphuric acid A
• Boric acid B
• Nitric acid C
• Phosphorus acid 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

Which of the following is a strong electrolyte?

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

• Cu A
• H B
• N C
• O 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

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

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

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

An electrochemical cell is based upon

• Acid-base reaction A
• Redox reaction B
• Nuclear reaction C
• None of the above 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

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

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

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

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 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

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

During redox reaction an oxidizing agent

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

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 an electrolytic cell, the electrons flow from :

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