# Electrochemistry Test 2

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

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

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

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

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

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

## Questions 2 of 50

Question:When lead storage battery is charged

$$Pb{O_2}$$is dissolved

$${H_2}S{O_4}$$is regenerated

$$PbS{O_4}$$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

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

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

$$C{u^{ + 2}}|Cu||Pt|Ag$$

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

Weston cell

Daniel cell

Calomel cell

Standard cell

## Questions 5 of 50

Question:A depolarizer used in dry cell batteries is

Ammonium chloride

Manganese dioxide

Potassium hydroxide

Sodium phosphate

## Questions 6 of 50

Question:When a lead storage battery is discharged

$$F{e^{2 + }}$$is evolved

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

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

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

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

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

39%

3.90%

0.35%

0.04%

## Questions 12 of 50

Question:The unit $$oh{m^{ - 1}}$$ is used for

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

Kohlrausch's equation

Nernst's equation

Ohm's equation

## Questions 14 of 50

Question:The correct representation of Nernst's equation is

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

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

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

None of the above

## Questions 15 of 50

Question:Standard electrode potential of $$NHE$$ at 298 K is

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

$$- ve,\, > 1,\, + ve$$

$$+ ve,\, > 1,\, - ve$$

$$- ve,\, < 1,\, - ve$$

$$- ve,\, > 1,\, - ve$$

## Questions 17 of 50

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

$$ZnC{l_2}$$

$$CuS{O_4}$$

$$H{g_2}C{l_2}$$

$$HgC{l_2}$$

## Questions 18 of 50

Question:The charge over anode in a galvanic cell is

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

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

Positive

Negative

Zero

Infinite

## Questions 21 of 50

Question:Which substance eliminates bromine from $$KBr$$ solution

$${I_2}$$

$$C{l_2}$$

$$HI$$

$$S{O_2}$$

## 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

$$- 0.42\,V$$

$$- \,2.20\,V$$

$$0.52\,V$$

$$1.04\,V$$

## Questions 23 of 50

Question:If the reduction potential is more, then

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 $$Hg$$

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

$$F{e^{2 + }}$$

$$Zn$$

$$Cr$$

$${H_2}$$

## 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

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

$$1 \times {10^{ - 10}}$$

$$29.5 \times {10^{ - 2}}$$

10

$$1 \times {10^{10}}$$

## Questions 28 of 50

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

$$Cl$$

$$F$$

$$Br$$

$$I$$

## 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

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

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

$$Cu$$

$$Al$$

$$Na$$

$$Au$$

## 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

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

-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

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

$$Na$$

$${H_2}$$

$$S{O_2}$$

$$S{O_3}$$

## Questions 36 of 50

Question:Electrolysis involves oxidation and reduction respectively at

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

Has a low boiling point

Is almost totally unionized

Is neutral

## Questions 38 of 50

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

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

1 ampere

1 coulomb

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

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 $$A{l^{3 + }}$$

$$96500\,\,C$$

$$\frac{{96500}}{3}C$$

$$\frac{{96500}}{2}C$$

$$3 \times 96500\,\,C$$

## Questions 42 of 50

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

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

$$m\,\, \propto {I^2}$$

$$m\,\, \propto Q$$

$$m\,\, \propto \,\,{Q^2}$$

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

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

2.24 litres

11.2 litres

1.12 litres

5.6 litres

## Questions 46 of 50

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

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

$$NaCl$$

$$BaC{l_2}$$

$$CuS{O_4}$$

$$AlC{l_3}$$

## Questions 49 of 50

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

$$11.2\;d{m^3}$$

$$5.6\,d{m^3}$$

$$22.4\;d{m^3}$$

$$1.0\;d{m^3}$$

## Questions 50 of 50

Question:Charge required to liberate 11.5 g sodium is