CBSE Questions for Class 12 Engineering Chemistry Electrochemistry Quiz 6 - MCQExams.com

During the process of electrolysis of water, dilute sulphuric acid splits into
  • Oxygen ions and hydrogen ions
  • Oxygen ions, hydrogen ions and sulphur ions
  • Hydrogen ions, and suplphate ions
  • None of these
An acid is a substance that produces ............. ions in a water solution
  • oxygen
  • nitrogen
  • carbon
  • hydrogen
In an electrolyte solution, current is maintained by the flow of:
  • electrons only
  • negative ions only
  • positive ions only
  • negative and positive ions both.
Water is decomposed into hydrogen and oxygen by means of electric current by the process:
  • electrolysis
  • electric heating
  • electroplating
  • None of these
The active materials used in lead-acid battery are
  • Spongy lead and lead oxide $$(PbO_2)$$
  • $$PbO_2$$ and $$Pb_2O_3$$
  • Spongy lead and $$Pb_2O_3$$
  •  only   $$PbO_2$$ 
In a dry cell _______ containing a moist paste of plaster of Paris, $$NH_4Cl$$ and $$ZnCl$$ acts as
  • Copper vessel, Cathode
  • Zinc vessel, Cathode
  • Zinc vessel, Anode
  • Copper vessel, Anode
________ can be obtained from bauxite by ______.
  • Aluminium, Electrolysis
  • Copper, Electroplating
  • Aluminium, Electroplating
  • Copper, Electrolysis

The compounds which decompose on passage of an electric current through them are known as :
  • electrolytes
  • non-electrolytes
  • electrolytically compounds
  • non-electrolytically compounds

The compounds which do not decompose on passage of an electric current through them are known as:
  • electrolytes
  • non-electrolytes
  • electrolytically compounds
  • non-electrolytically compounds
An article made of an ordinary metal is desired to be coated with gold by electroplating, then gold has to be:
  • Made as the electrolyte of the electrolytic cell.
  • Made as the anode of an electrolytic cell.
  • Made as the connecting wire in the electrolytic cell.
  • Kept immersed in the electrolyte solution.
Ammonium chloride used in dry cell acts as
  • Catalyst
  • Electrolyte
  • Polariser
  • Both $$(1)$$ and $$(3)$$
Electrolysis is due to the ______ effect of electric current.
  • chemical
  • heating
  • mechanical
  • none
Lead acid cell and alkalic cells are
  • Storage cells
  • Accumulators
  • Secondary cells
  • All of these

The process used to decompose compounds using electric current is called :
  • electrolysis
  • electrification
  • currents
  • electrolytic process
The most common industrial application of chemical effects of electric current is
  • electroplating
  • galvanising
  • anodising
  • electrolysis
A Faraday is:
  • the magnitude of the charge of 1 mole of electrons.
  • the magnitude of the electric dipole.
  • a fundamental constant of nature equal to $$\displaystyle 6.63\times { 10 }^{ -34 }Js/photon$$.
  • a constant that accounts for the existence of ions in solution.
Tin cans, used for storing food are made by electroplating
  • chrome onto tin
  • iron onto tin
  • tin onto iron
  • chrome onto iron
Select incorrect statement
  • If salt-bridge is removed, potential falls to zero
  • Liquid-junction potential developed across the boundary of the two solutions of different concentration cells are used
  • Calomel electrode contains calcium chloride solution in contact with $$Pt$$ electrode
  • Quinhydrone electrode is reversible to $${H}^{+}$$

What should be the state of compounds which decompose on passing electric current?
  • Plasma
  • Solid
  • Gas
  • Molten or aqueous
Anode is
  • positively charged electrode
  • negatively charged electrode
  • wire used to connect the electrodes
  • electrolyte which conducts electricity
Electrolytes which allow small amount of electricity to pass through them are known as :
  • strong electrolytes.
  • weak electrolytes.
  • non-electrolytes.
  • none of the above.
Carbon dioxide is a  __________.
  • weak electrophile
  • weak nucleophile
  • ambident species
  • none of these
The process in which chemical change occurs on passing electricity is termed as __________.
  • ionisation
  • neutralisation
  • electrolysis
  • hydrolysis
The following factors play vital role in corrosion process:
  • Temperature
  • Pressure
  • Moisture
  • All of the above

The electric charge for electrode deposition of 1gm. Equivalent of a substance is: 
  • 96,500 coulombs
  • one ampere per sec
  • one ampere for one hour
  • charge in faradays
The cathode in the central compartment of Castner Kellner cell used for the manufacture of $$NaOH$$ is:
  • Iron
  • Carbon
  • Mercury
  • Steel

In a galvanic cell electron flow will be from:
  • negative electrode to positive electrode
  • positive electrode to negative electrode
  • there will be no flow of electrons
  • cathode to anode in the extenal circuit
A reversible galvanic cell is connected to an external battery. If the EMF of the battery is less than the EMF of the galvanic cell, then the current:
  • will not pass through the circuit
  • will flow from the battery to the galvanic cell
  • will flow from the galvanic cell to the battery
  • can flow in any direction

In a galvanic cell, the reactions taking place in the anodic half cell and the cathodic half cell will be:
  • reduction
  • oxidation
  • oxidation and reduction respectively
  • reduction and oxidation respectively
A half cell reaction is one which:
  • involves only half a mole of electrolyte
  • goes only half way to completion
  • takes place at one electrode
  • consumes half a unit of electricity

An aqueous solution of the following concentration of Acetic acid is the best conductor.
  • 10$$^{1}$$M
  • 10$$^{-3}$$M
  • 10$$^{-1}$$M
  • 10$$^{2}$$M

Which of the following is not true?
  • The electrode which pushes electrons into external circuit is known as anode
  • The electrode which pulls electrons out of external circuit is known as cathode
  • Weak electrolytes conduct relatively small quantity of electricity than strong electrolytes
  • Effect of dilution on conductance of strong electrolyte can be explained by Arrhenius theory.
In an electrolytic cell, the current flows from:
  • cathode to anode in outer circuit
  • anode to cathode outside the cell
  • cathode to anode inside the cell
  • current does not flow

Zinc corrodes in ____________________.
  • $$2M$$ alkaline solution
  • $$2M$$ acid solution
  • $$2M$$ neutral salt solution
  • all of the above

The EMF of a galvanic cell is determined by using a:
  • voltmeter
  • potentiometer
  • coulometer
  • ammeter

$$ Cu(S) + 2Ag^{+}(aq) \rightarrow Cu^{2+}(aq)+2Ag(S) $$

In the given reaction, the reduction half cell reaction is:
  • $$Cu$$ $$^{2+}$$ $$+$$ $$2e$$$$^{-}$$ $$\rightarrow $$ $$Cu$$
  • $$Cu$$ $$-$$ $$2e$$ $$^{-}$$$$\rightarrow $$$$Cu$$$$^{2+}$$
  • $$Ag$$ $$^{+}$$ $$+$$  e$$^{-}$$$$\rightarrow $$ $$Ag$$
  • $$Ag$$  $$-$$  $$e$$ $$^{-}$$$$\rightarrow $$ $$Ag$$ $$^{+}$$
In corrosion of iron,
  • electrons flow from anode to cathode through the metal, while ions flow through the water droplets
  • an electrochemical (galvanic) cell is formed in which $$Fe$$ acts as anode and $$O_{2}$$ is reduced at cathode
  • dissolved $$O_{2}$$ oxidizes $$Fe^{2+}$$ to $$Fe^{3+}$$ before it is deposited as rust $$(Fe_{2}O_{3}.xH_{2}O)$$
  • All of the above takes place

In which of the following the corrosion of iron will be most rapid?
  • In pure water
  • In pure oxygen
  • In air and moisture
  • In air and saline water
In the electrolytic cell, flow of electrons is from:
  • cathode to anode in solution
  • cathode to anode through external supply
  • cathode to anode through internal supply
  • anode to cathode through internal supply

Schematic diagram of an electrolytic-cell is:
  • none is correct presentation

For the cell reaction : $$C{u^{2 + }}(aq)({C_1}) + Zn(s) \to Z{n^{2 + }}(aq)({C_2}) + Cu(s)$$ the change in free energy $$\Delta G$$ at a given temperature is a function of
  • $$ln C_1$$
  • $$ln (\dfrac{C_2}{C_1})$$
  • $$ln (C_2+ C_2)$$
  • $$ln (C_2)$$
Corrosion of iron pipes occurs in the presence of water. To prevent such corrosion, iron pipes are normally coated with an element like magnesium using electroplating.
Which of the following statements is correct?
  • During corrosion of an un-plated iron pipe, iron is reduced; during electroplating, magnesium is deposited on the cathode.
  • During corrosion of an un-plated iron pipe, water is oxidized; during electroplating, iron acts as anode.
  • During corrosion of an un-plated iron pipe, oxygen is reduced; during electroplating, iron acts as cathode.
  • During corrosion of an un-plated iron pipe, iron is oxidised; during electroplating, magnesium is deposited on the anode.
Electrolysis involves conversion of chemical energy to electrical energy.
  • True
  • False
One Faraday is equal to ___________.
  • 69500 coulombs
  • 91500 coulombs
  • 91400 coulombs
  • 96500 coulombs
The presence of $$CO_2$$ in the atmosphere results in:
  • rusting.
  • dusting.
  • electroplating.
  • freezing.
The process of depositing a thin layer of desired metal over another metal by passing an electric current through some electrolyte is called as ?
  • electroplating
  • oxidation
  • electrotyping
  • electric shielding.
In electrochemical cell, oxidation and reduction occurs at:
  • anode and cathode respectively
  • cathode and anode respectively
  • electrode
  • anode only
The battery is an arrangement of an electrolytic cell connected in series.
  • True
  • False
When the terminals of a cell of e.m.f. 1.5V are connected to an ammeter of resistance $$4\Omega$$, the ammeter read 0.30 amp. which of the following statements is/are correct?
  • The cell is non-ideal
  • If a $$4\Omega$$ resistor is also connected across terminals of the cell, the ammeter will read 0.50 amp.
  • If a $$4\Omega$$ resistor is also connected across terminals of the cell, one-third of the electrical power generated will dissipate as heat within the cell.
  • If a voltmeter of resistance $$4\Omega$$ is used to measure potential difference between terminals of the cell, it will read 1.2 V.
Which of the following methods is suitable for preventing an iron frying pan from rusting?
  • Applying grease
  • Applying paint
  • Applying a coating of zinc
  • All of the above.
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