.A certain current liberated 0.504 g of hydrogen in 2 hours. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution? 22.9 g
1.63.5 g
2.31.8 g
3.22.9 g
4.55.8 g
.Amount of chlorine liberated while passing 0.5 faraday of electricity through NaCl solution is
1.63 g
2.17.75 g
3.35.5 g
4.8.25 g
.Aqueous solution of HCl conducts electricity because it
1.dissociates
2.dimerises
3.ionises
4.forms hydrogen bond
.At infinite dilution of an electrolyte, the equivalent conductance of cations and anions are
1.dependent on the nature of solvent
2.independent of nature of ions
3.independent of each other
4.dependent on each other
.During discharge in the case of lead storage batteries density of sulphuric acid increases remains constant
1.increases
2.decreases
3.may decrease or increase
4.remains constant
.During the electrolysis of fused sodium chloride, the anodic reaction is
1.reduction of chloride ions
2.oxidation of sodium ions
3.oxidation of chloride ions
4.None of the above
.Electrolytes when dissolved in water dissociate into their constituent ions. The degree of dissociation of an electrolyte increase with the
1.decreasing concentration of the electrolyte
2.increasing concentration of the electrolyte
3.presence of a common constituent
4.decreasing temperature
.For reducing 1 mole of ferrous ions to iron the number of faradays of electricity required will be
1.4
2.1.5
3.0.5
4.1
.Hydroxide ions are discharged in reference to chloride ions when?.is electrolysed.
1.NaCl
2.solid NaCl
3.dil. NaCl
4.conc. NaCl
.In an electrochemical cell, electrical energy
1.may be absorbed or released
2.neither supplied nor released
3.has to be supplied
4.is released
.In electrolysis, one mole of aluminium atoms is deposited by
1.five moles of electrons
2.three moles of electrons
3.two moles of electrons
4.one mole of electrons
.On passing electricity through dil sulphuric acid the amounts of substance liberated at the cathode and anode are in the ratio
1.2:03
2.3:02
3.8:01
4.1:08
.On passing one faraday of electricity through molten lead (II) bromide, amount of bromine obtained is 1 gm equivalent
1.5 gm mole
2.5 gm mole
3.3 mole
4.1 mole gm atom
.Passing 96.5 coulombs of charge through molten NaOH will deposit
1.0.046 g
2.0.023 g
3.230 g
4.46 g
.The amount of electricity that can deposit 108 g of silver
1.1 amp.
2.1 coulomb
3.1 Faraday
4.2 amp.
.The chemical reaction taking place at anode is
1.halogenation
2.oxidation
3.ionisation
4.reduction
.The conduction of electricity through the electrolyte solution is due to
1.movement of molecules of electrolyte
2.movement of ions of electrolyte
3.movement of separate atoms
4.movement of particles of the solvent.
.The electrode by which electrons enter the electrolyte may be
1.cathode
2.conductor
3.anode
4.anode or cathode
.The most reactive metals among the following is Mg
1.Mg
2.Rb
3.Al
4.Na
.The quantity of an ion discharged during electrolysis is directly proportional to
1.chemical equivalent of the ion
2.time of flow of current
3.current strength
4.All the above
.The units of electrochemical equivalent is
1.gram/second
2.gram/coulomb
3.gram/cm
4.gram/volt
.Two electrolytic cell contain 0.1 M ferrous sulphate and 0.2 M ferric chloride respectively are subjected to electrolysis, the ratio of iron deposited in the two cells is
1.1:01
2.2:01
3.3:01
4.3:02
.Which of the following does not give conducting solution is water?
1.Potash alum
2.Ethyl alcohol
3.Vitriol
4.Methyl Alcohal
.Which of the following is not a good conductor?
1.Silver
2.Solid NaCl
3.Fused NaCl
4.Aqueous solution of NaCl
.Which of the following is the best reducing agent in aqueous solution?
1.Li
2.Cs
3.Rb
4.K
A bulb draws a current of 4.0 ampere, the charge in coulombs used by the bulb in 30 seconds is
1.60 C
2.120 C
3.15 C
4.7.5 C.
A certain quantity of current i amp was passed through three electrolytic cells P, Q, R connected in series and containing aqueous solutions of silver nitrate, mercuric nitrate and mer-curous nitrate respectively. It resulted in the deposition of0.216 g of Ag. The masses of Hg deposited in cell Q andR respectively (At. = 108; Hg = 200.6)
1.0.4012 g, 0.9042 g
2.0.4012 g, 0.2006 g
3.0.2006 g, 0.4012 g
4.0.1003 g, 0.2006 g.
An ampere is the rate of flow of electric current of:
1.one coulomb per second
2.one faraday per minute
3.one coulomb per minute
4.one faraday per second
An electrochemical cell can be changed into an electrolytic cell by
1.changing the electrolytes in two half cells
2.changing the conc. of the electrolytes
3.providing higher potential from outside
4.reversing the electrodes
Art of electroplating was enunciated by Brugantally
1.Einstein
2.Brugantally
3.Ampere
4.Kohlorausch
Certain quantity of current librated 0.504 g of hydrogen in 2 hr. The number of grams of copper that can be librated by same current under similar conditions will be approximately
1.12.7 g
2.16.0 g
3.31.8 g
4.63.5 g.
During the electrolysis of water 4 mol of electrons were transferred from anode to cathode. The total volume of the gases produced at STP will be approximately
1.67.2 L
2.22.4 L
3.44.8 L
4.89.4 L.
Electrochemical equivalent is the mass of the element liberated during electrolysis when
1.2 faraday electricity is passed
2.1 amp. current for 1 hrs is passed
3.1 coulomb electricity is passed
4.3 amp current is passed
If mercury is used at cathode during the electrolysis of aqueous NaCl the ions discharged at the cathode are
1.hydroxide
2.chloride
3.sodium
4.none of these
If the specific conductance and conductance of a solution are the same, then the cell constant is 8
1.25
2.10
3.8
4.9
In a galvanic cell, which one of the following statements is incorrect?
1.Reduction takes place at the anode
2.Reduction takes place at the cathode
3.Cathode is positively charged
4.Anode is negatively charged
In the concentration cells the electrical energy is due to
1.transfer of a substance from one solution to another solution
2.temperature
3.reduction of fuel
4.chemical action
It is impossible to measure the actual voltage of any half cell by itself because
1.of resistance of wire
2.electrical neutrality is maintained
3.a reaction does not take place of its own
4.both half cell reactions occur simultaneously
More electropositive elements have more
1. negative reduction potential
2.positive oxidation potential
3.tendency to loose electrons
4.positive reduction potential
One mole of electrons is same as faraday
1.faraday
2.coulomb
3.ampere
4.none of these
Point out the correct statement in a cell of zinc and copper:
1.Zinc acts as anode and copper as cathode
2.The E of zinc is more than that of copper
3.The flow of electrons is from copper to zinc
4.Zinc acts as cathode and copper as anode
Salt Bridge is used because it
1.forms insoluble precipitates with the electrolytes in the two half cells
2.enhances the flow of electrons by overcoming liquid junction potential
3.maintains the electrical neutrality of the two half cells
4.provides the extra ions
Substances that dissociate and conduct electricity in aqueous solutions are conductors
1.emulsios
2.colloidal solution
3.electrolytes
4.conductors
The conductivity of strong electrolyte increase on dilution slightly
1.increase on dilution slightly
2.does not change on dilution
3.decreases on dilution
4.depends on density of electrolyte itself.
The decomposition of an electrolyte by passing electric current depends upon
1.energy of electrolysis
2.quantity of current which is passed
3.shape of the electrode
4.size of the container
The equivalent conductivity of a weak electrolyte
1.increases rapidly with dilution but does not reach a
2.constant value even at infinite dilution
3.reaches a maximum constant value at infinite dilution
4.is a constant and does not change with dilution
The most important condition for a galvanic cell is
1.the two half cells should be connected internally by some device
2.the electrolytes should taken in a separate container
3.the electrolytes should not have physical contact
4.the electrodes should be inert
Voltaic cell stops functioning after sometimes because there is increase in oxidation potential and decrease in reduction potential
1.the decrease in oxidation potential outweigh the increase in reduction potential
2.the decrease in oxidation potential value equalises the increase in reduction potential value
3.decrease in oxidation potential value
4.increase in oxidation potential and decrease in reduction potential
When electricity is passed to aqueous solution of aluminium chloride, 13.5 g of Al are deposited. The number of Faradys of electricity passed must be
1.2
2.1.5
3.1
4.0.5
Which of the following metals when coupled will give maximum e.m.f. for a voltaic cell.
1.Pb and Sn
2.Cu and Ag
3.Ca and Cu
4.Fe and Cu