ECAT Pre Engineering Chemistry Chapter 10 MCQ Test With Answer

• Zn A
• H B
• S C
• O D

Metals like Fe, Mg, Al, Cr, Zn have more negative reduction potentials that is whey

• These don't react with steam A
• These react very slowly with steam to liberate H₂gas B
• These react rapidly with steam to produce the metallic oxides and liberate H₂gas C
• These react with cold water violently 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

Which of the following statements is true about Galvanic cell

• Anode is negatively charged A
• Reduction occurs at anode B
• Cathode is positively charge C
• Reduction occurs at cathode 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

If the salt bridge is not used between two half cells, then the voltage

• Decrease rapidly A
• Decrease slowly B
• Does not change C
• Drops to zero D

Metallic conduction is also called as :

• Ionic conduction. A
• Protonic conduction. B
• Electronic conduction C
• Super conduction D

In electrolysis of NaCl when Pt electrode is taken then H₂is liberated at cathode while with Hg cathode it forms sodium amalgam

• Hg is more inert than Pt A
• More voltage is required to deduce H⁺at Hg than Pt B
• Na is dissolved in Hg while it does not dissolve in Pt C
• Conc. of H⁺ions is larger when Pt electrode is taken 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

Specific conductivity of a solution

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

During electrolysis of KNO₃, H₂is evolved

• Anode A
• Cathode B
• Both a and b C
• None D

The reference calomel electrode is made from which of the following?

• ZnCl₂ A
• CuSO₄ B
• Hg₂Cl₂ C
• HgCl₂ D

• Cu A
• H B
• N C
• O 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

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

Electrochemistry is concerned with the conversion of electrical energy into chemical energy in :

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

A standard hydrogen electrode is used as standard electrode of which electrode potential is arbitrarily taken as

• +1 A
• -1 B
• 0.1 C
• Zero D

Which of the following is a strong electrolyte?

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

• A strong reducing agent A
• A strong oxidising agent B
• Better oxidising agent than hydrogen C
• Less reducing agent than hydrogen 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 value of SHE is cathode and anode is always taken to be

• One A
• Zero B
• Different C
• Same 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 oxidation number of chromium in K₂Cr₂O₇is

• 14 A
• 12 B
• 6 C
• None of these D

Which of the following cannot conduct electricity :

• NaCl fused. A
• NaCl(aq)
  B
• NaCl(Solid)
  C
• Both (b) and (c) 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

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

The electrode through which the electrons enter the electrolytic solution is electrolytic solution is

• Anode A
• Cathode B
• May be anode or cathode C
• None of these D

During redox reaction an oxidizing agent

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