ECAT Pre Engineering Chemistry Chapter 10 MCQ Test With Answer

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

The galvanic or voltaic cells which are rechargeable called as

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

The specific conductance of a 0.1 N KCl solution at 23°C is 0.012 ohm^-1cm^-1. The resistance of cell containing the solution at the same temperature was found to be 55 ohm. The cell constant will be

• 0.142 cm^-1 A
• 0.66 cm^-1 B
• 0.916 cm^-1 C
• 1.12 cm^-1 D

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

In a Galvanic cell, the electrons flow from

• A node to cathode through the solution A
• Cathode to anode through the external circuit B
• Cathode to anode through the external circuit C
• Anode to cathode through the external circuit 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

An electrochemical cell is based upon

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

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

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

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

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 conversion of chemical energy into electrical energy requires :

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

Which of the following statement is incorrect about SHE(Standard hydrogen electrode):

• Reduction potential of Cu⁺² is smaller than H⁺ions whenit is coupled with copper electrode. A
• gas is passed in it at 1 atm pressure. B
• Its oxidation potential and reduction potential is zero. C
• It is made of platinum wire dipped in HCl solution 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

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

Alkaline battery has a voltage of

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

The number of coulombs required for the deposition of 107.870 g of silver is

• 96500 A
• 48250 B
• 193000 C
• 10000 D

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

Which of the following is the use of electrolysis?

• Eletrorefining A
• Electroplating B
• Both A and B C
• None of the above 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 will be good conductor of electricity

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

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

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

In passage of electricity through aqueous solution of AgNO₃silver dissolves at anode to form Ag⁺, the electrodes are

• Silver metal A
• Pt metal B
• Graphite C
• Copper metal 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

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

In KO₂the oxidation state of oxygen is

• -2 A
• -1 B
• +1/2 C
• -1/2 D

• Zn A
• H B
• S C
• O D

Which statement is correct for the fuel cells

• These cells operate at low temperature A
• These cells operate at low temperature B
• No catalyst used for the formation of water C
• MnO₂is used as electrolyte D