Electrochemistry Test 2

Total Questions:50 Total Time: 75 Min

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Questions 1 of 50

Question:Which of the following reaction is used to make a fuel cell

Answers Choices:

\(Cd(s) + 2Ni{(OH)_3}(s) \to CdO(s) + 2Ni(OH) + {H_2}O(l)\)

\(Pb(s) + Pb{O_2}(s) + 2{H_2}S{O_4}(aq) \to 2PbS{O_4}(s) + 2{H_2}O(l)\)

\(2{H_2}(g) + {O_2}(g) \to 2{H_2}O(l)\)

\(2Fe(s) + {O_2}(g) + 4{H^ + }(aq) \to 2F{e^{2 + }}(aq) + 2{H_2}O(l)\)

Questions 2 of 50

Question:When lead storage battery is charged

Answers Choices:

\(Pb{O_2}\)is dissolved

\({H_2}S{O_4}\)is regenerated

\(PbS{O_4}\)is deposited on lead electrode

Lead is deposited on lead electrode

Questions 3 of 50

Question:The cell reaction \(Cu + 2A{g^ + } \to C{u^{ + 2}} + Ag\) is best represented by

Answers Choices:

\(C{u_{(s)}}|C{u^{ + 2}}_{(aq)}||A{g^ + }_{(aq)}|A{g_{(s)}}\)

\(Pt|C{u^{ + 2}}||A{g^ + }_{(aq)}|A{g_{(s)}}\)

\(C{u^{ + 2}}|Cu||Pt|Ag\)

None of the above representations

Questions 4 of 50

Question:\(\mathop {Z{n_{(s)}}|Z{n^{2 + }}_{(aq)}|}\limits_{{\rm{(anode)}}\,\,\,\,\,\,\,\,\,\,\,\,\,} |\mathop {C{u^{2 + }}_{(aq)}|C{u_{(s)}}}\limits_{{\rm{(cathode)}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \)is

Answers Choices:

Weston cell

Daniel cell

Calomel cell

Faraday cell

Standard cell

Questions 5 of 50

Question:A depolarizer used in dry cell batteries is

Answers Choices:

Ammonium chloride

Manganese dioxide

Potassium hydroxide

Sodium phosphate

Questions 6 of 50

Question:When a lead storage battery is discharged

Answers Choices:

\(F{e^{2 + }}\)is evolved

Lead sulphate is consumed

Lead is formed

Sulphuric acid is consumed

Questions 7 of 50

Question:At 25\(^\circ \)C specific conductivity of a normal solution of KCl is 0.002765 mho. The resistance of cell is 400 ohms. The cell constant is

Answers Choices:

0.815

1.016

1.106

2.016

Questions 8 of 50

Question:Which of the following is used widely in the manufacture of lead storage battery

Answers Choices:

Arsenic

Lithium

Bismuth

Antimony

Questions 9 of 50

Question:The increase in equivalent conductance of an electrolyte solution with dilution is due to the increase in

Answers Choices:

Ionic attraction

Molecular attraction

Degree of association of the electrolyte

Degree of ionisation of the electrolyte

Questions 10 of 50

Question:Which of the following conducts electricity

Answers Choices:

Fused \(NaCl\)

\(C{O_2}\)

\(B{r_2}\)

\(Si\)

Questions 11 of 50

Question:If equivalent conductance of \(1M\) benzoic acid is \(12.8oh{m^{ - 1}}c{m^2}\) and if the conductance of benzoate ion and \({H^ + }\) ion are 42 and \(288.42\,oh{m^{ - 1}}c{m^2}\) respectively. its degree of dissociation is

Answers Choices:

39%

3.90%

0.35%

0.04%

Questions 12 of 50

Question:The unit \(oh{m^{ - 1}}\) is used for

Answers Choices:

Molar conductivity

Equivalent conductivity

Specific conductivity

Conductivity

Questions 13 of 50

Question:The name of equation showing relation between electrode potential \((E)\)standard electrode potential \(({E^o})\) and concentration of ions in solution is

Answers Choices:

Kohlrausch's equation

Nernst's equation

Ohm's equation

Faraday's equation

Questions 14 of 50

Question:The correct representation of Nernst's equation is

Answers Choices:

\({E_{{M^{n + }}/M}} = {E^o}_{{M^{n + }}/M} + \frac{{0.0591}}{n}\log \,({M^{n + }})\)

\({E_{{M^{n + }}/M}} = {E^o}_{{M^{n + }}/M} - \frac{{0.0591}}{n}\log \,({M^{n + }})\)

\({E_{{M^{n + }}/M}} = {E^o}_{{M^{n + }}/M} + \frac{n}{{0.0591}}\log \,({M^{n + }})\)

None of the above

Questions 15 of 50

Question:Standard electrode potential of \(NHE\) at 298 K is

Answers Choices:

0.05 V

0.1 V

0.00 V

0.11 V

Questions 16 of 50

Question:For a spontaneous reaction the \(\Delta G,\) equilibrium constant (K) and \(E_{Cell}^o\) will be respectively

Answers Choices:

\( - ve,\, > 1,\, + ve\)

\( + ve,\, > 1,\, - ve\)

\( - ve,\, < 1,\, - ve\)

\( - ve,\, > 1,\, - ve\)

Questions 17 of 50

Question:The reference electrode is made from which of the following

Answers Choices:

\(ZnC{l_2}\)

\(CuS{O_4}\)

\(H{g_2}C{l_2}\)

\(HgC{l_2}\)

Questions 18 of 50

Question:The charge over anode in a galvanic cell is

Answers Choices:

Negative

Positive

No charge

Sometimes negative and sometimes positive

Questions 19 of 50

Question:Standard electrode potential of \(A{g^ + }/Ag\) and \(C{u^ + }/Cu\) is \( + 0.80V\) and \( + 0.34V\) respectively. these electrodes are joint together by salt bridge if

Answers Choices:

Copper electrode is work like cathode, then \(E_{cell}^o\) is \( + 0.45V\)

Silver electrode is work like anode then \(E_{cell}^o\) is \( - 0.34V\)

Copper electrode is work like anode then \(E_{cell}^o\) is \( + 0.46V\)

Silver electrode is work like cathode then \(E_{cell}^o\) is \( - 0.34V\)

Silver electrode is work like anode then \(E_{cell}^o\) will be \( + 1.14V\)

Questions 20 of 50

Question:The reaction is spontaneous if the cell potential is

Answers Choices:

Positive

Negative

Zero

Infinite

Questions 21 of 50

Question:Which substance eliminates bromine from \(KBr\) solution

Answers Choices:

\({I_2}\)

\(C{l_2}\)

\(HI\)

\(S{O_2}\)

Questions 22 of 50

Question:The standard electrode potential \(({E^o})\) for \(OC{l^ - }/C{l^ - }\) and \(C{l^ - }/\frac{1}{2}C{l_2}\) respectively are \(0.94\,V\) and \( - 1.36\,V\). The \({E^o}\) value for \(OC{l^ - }/\frac{1}{2}C{l_2}\) will be

Answers Choices:

\( - 0.42\,V\)

\( - \,2.20\,V\)

\(0.52\,V\)

\(1.04\,V\)

Questions 23 of 50

Question:If the reduction potential is more, then

Answers Choices:

It is easily oxidized

It is easily reduced

It acts as oxidising agent

It has redox nature

Questions 24 of 50

Question:One of the following is false for \(Hg\)

Answers Choices:

It can evolve hydrogen from \({H_2}S\)

It is a metal

It has high specific heat

It is less reactive than hydrogen

Questions 25 of 50

Question:\(Z{n^{2 + }} + 2{e^ - } \to Zn(s);{E^o} = - \,0.76\), \(F{e^{3 + }} + {e^ - } \to F{e^{2 + }};{E^o} = - \,0.77\),\(C{r^{3 + }} + 3{e^ - } \to Cr;{E^o} = - \,0.79\), \({H^ + } + 2{e^ - } \to 1/2{H_2}\,;\,{E^o} = 0.00\) Strongest reducing agent is

Answers Choices:

\(F{e^{2 + }}\)

\(Zn\)

\(Cr\)

\({H_2}\)

Questions 26 of 50

Question:Standard reduction electrode potentials of three metals A, B and C are respectively + 0.5V, – 3.0V and – 1.2 V. The reducing powers of these metals are

Answers Choices:

B > C > A

A > B > C

C > B > A

A > C > B

Questions 27 of 50

Question:For a cell reaction involving a two-electron change, the standard emf of the cell is found to be 0.295 V at \({25^o}C\). The equilibrium constant of the reaction at \({25^o}C\) will be

Answers Choices:

\(1 \times {10^{ - 10}}\)

\(29.5 \times {10^{ - 2}}\)

10

\(1 \times {10^{10}}\)

Questions 28 of 50

Question:The element which can displace three other halogens from their compound is

Answers Choices:

\(Cl\)

\(F\)

\(Br\)

\(I\)

Questions 29 of 50

Question:Which of the following has been universally accepted as a reference electrode at all temperatures and has been assigned a value of zero volt

Answers Choices:

Graphite electrode

Copper electrode

Platinum electrode

Standard hydrogen electrode

Questions 30 of 50

Question:Aluminium is more reactive than \(Fe\). But \(Al\)is less easily corroded than iron because

Answers Choices:

Al is noble metal

Iron forms both mono and divalent ions

Oxygen forms a protective oxide layer

Fe undergoes reaction easily with \({H_2}O\)

Questions 31 of 50

Question:The metal that forms a self protecting film of oxide to prevent corrosion, is

Answers Choices:

\(Cu\)

\(Al\)

\(Na\)

\(Au\)

Questions 32 of 50

Question:In a cell that utilises the reaction \(Z{n_{(s)}} + 2{H^ + }(aq) \to \) \(Z{n^{2 + }}(aq) + {H_{ & 2(g)}}\)addition of \({H_2}S{O_4}\) to cathode compartment, will

Answers Choices:

Increase the E and shift equilibrium to the right

Lower the E and shift equilibrium to the right

Lower the E and shift equilibrium to the left

Increase the E and shift equilibrium to the left

Questions 33 of 50

Question:The rusting of iron takes place as follows 2H+ + 2e- + ½O\( \to \)\(_{\rm{2}}\)\( \to \) H\(_{\rm{2}}\)O(l) ; E\(^\circ \) = +1.23 V Fe\(^{{\rm{2}} + }\) + 2e- Fe(s) ; E\(^\circ \) = -0.44 V. Calculate DG° for the net process

Answers Choices:

-322\(\kappa \nu \mu o{\lambda ^{ - 1}}\)

-161\(\kappa \nu \,\mu o{\lambda ^{ - 1}}\)

-152\(\kappa \nu \,\mu o{\lambda ^{ - 1}}\)

-76 \(\kappa \nu \,\mu o{\lambda ^{ - 1}}\)

Questions 34 of 50

Question:When an acid cell is charged, then

Answers Choices:

Voltage of cell increases

Electrolyte of cell dilutes

Resistance of cell increases

None of these

Questions 35 of 50

Question:On the electrolysis of aqueous solution of sodium sulphate, on cathode we get

Answers Choices:

\(Na\)

\({H_2}\)

\(S{O_2}\)

\(S{O_3}\)

Questions 36 of 50

Question:Electrolysis involves oxidation and reduction respectively at

Answers Choices:

Anode and cathode

Cathode and anode

At both the electrodes

None of the above

Questions 37 of 50

Question:Pure water does not conduct electricity because it

Answers Choices:

Has a low boiling point

Is almost totally unionized

Is neutral

Is readily decomposed

Questions 38 of 50

Question:Which is responsible for electrical conduction of molten sodium chloride

Answers Choices:

Free electrons

Free ions

Free molecules

Atoms of sodium and chlorine

Questions 39 of 50

Question:Amount of electricity that can deposit 108 gm of silver from AgNO\(_{\rm{3}}\) solution is

Answers Choices:

1 ampere

1 coulomb

1 faraday

None of the above

Questions 40 of 50

Question:When 9.65 coulombs of electricity is passed through a solution of silver nitrate (atomic weight of \(Ag = 107.87\) taking as 108) the amount of silver deposited is

Answers Choices:

10.8 mg

5.4 mg

16.2 mg

21.2 mg

Questions 41 of 50

Question:The desired amount of charge for obtaining one mole of \(Al\) from \(A{l^{3 + }}\)

Answers Choices:

\(96500\,\,C\)

\(\frac{{96500}}{3}C\)

\(\frac{{96500}}{2}C\)

\(3 \times 96500\,\,C\)

Questions 42 of 50

Question:One Faraday of electricity when passed through a solution of copper sulphate deposits

Answers Choices:

1 mole of \(Cu\)

1 gm atom of \(Cu\)

1 molecule of \(Cu\)

1 gm equivalent of \(Cu\)

Questions 43 of 50

Question:Electrolysis rules of Faraday’s states that mass deposited on electrode is proportional to

Answers Choices:

\(m\,\, \propto {I^2}\)

\(m\,\, \propto Q\)

\(m\,\, \propto \,\,{Q^2}\)

None of these

Questions 44 of 50

Question:A current being passed for two hour through a solution of an acid liberating 11.2 litre of oxygen at NTP at anode. What will be the amount of copper deposited at the cathode by the same current when passed through a solution of copper sulphate for the same time

Answers Choices:

16 g

63 g

31.5 g

8 g

Questions 45 of 50

Question:During electrolysis of fused aluminium chloride \(0.9\,gm\) of aluminium was deposited on the cathode. The volume of chlorine liberated at the anode will be

Answers Choices:

2.24 litres

11.2 litres

1.12 litres

5.6 litres

Questions 46 of 50

Question:Faraday has the dimensions of

Answers Choices:

Coulombs

Coulomb equivalent

Coulomb per equivalent

Coulomb per degree Kelvin

Questions 47 of 50

Question:The mass deposited at an electrode is directly proportional to

Answers Choices:

Atomic weight

Equivalent weight

Molecular weight

Atomic number

Questions 48 of 50

Question:From the solution of which of the following one faraday of electricity will liberate one gram atom of metal

Answers Choices:

\(NaCl\)

\(BaC{l_2}\)

\(CuS{O_4}\)

\(AlC{l_3}\)

Questions 49 of 50

Question:When 1F of electricity is passed through acidulated water, \({O_2}\)evolved is

Answers Choices:

\(11.2\;d{m^3}\)

\(5.6\,d{m^3}\)

\(22.4\;d{m^3}\)

\(1.0\;d{m^3}\)

Questions 50 of 50

Question:Charge required to liberate 11.5 g sodium is

Answers Choices:

0.5 F

0.1 F

1.5 F

96500 coulombs