JEE Main Chemistry - Electrochemistry
Exam Duration: 60 Mins Total Questions : 30
When an aqueous solution of sulphuric acid is electrolysed using platinum electrodes, the products of electrolysis are
- (a)
hydrogen and oxygen
- (b)
hydrogen and hydroxyl ion
- (c)
hydrogen and sulphate ion
- (d)
oxygen and sulphate ion
In the above question,the ion discharged at the anode is
- (a)
hydrogen
- (b)
oxygen
- (c)
hydrogen
- (d)
sulphate
When an aqueous solution or concentrated solution of NaOH is electrolysed using platinum electrode,the ion discharged at the cathode is
- (a)
sodium
- (b)
hydrogen
- (c)
hydroxyl
- (d)
oxygen
The amount of charge required for the deposition of 1g equivalent of substance is
- (a)
one ampere for one second
- (b)
one ampere for one hour
- (c)
96500 coulombs
- (d)
96500 Faradays
The equivalent conductance at infinite dilution of HCl and NaCl are 426.15 and 126.115 ohm-1 cm2 eq-1 respectively,It can be said that the mobility of
- (a)
H+ ions is much more than that of Na+ ions
- (b)
H+ ions is much more than that of Cl-? ions
- (c)
Na+ ions is much more than that of H+ ions
- (d)
Cl- ions is much more than that of Na+ ions
2.5 faraday of electricity are passed through a solution of CuSO4 .The number of gram equivalent of Cu deposited on the anode would be
- (a)
0
- (b)
2
- (c)
1.25
- (d)
1.24
The current in a given wire is 1.8 A .The number of coulombs that will pass through a given wire in 1.36 minutes would be
- (a)
100c
- (b)
147c
- (c)
247c
- (d)
347c
The following are balanced half-reaction equations.Which one of them represents reduction process?
- (a)
\(Fe^{2+}\longrightarrow Fe^{3+}+e\)
- (b)
\(Mn_4^{-}+8H^++5e\longrightarrow M^{2+}+4H_2o\)
- (c)
\(H_2S\longrightarrow S+2H^{+}+2e\)
- (d)
\(OH^{-}\longrightarrow 2H_2O+O_2+4e\)
if the standard reduction potential of copper Cu2+/Cu is 0.337 volt,the potential for the following cell H2(g)/H+ (aq)(1M)||Cu2+(aq)|Cu(s)
- (a)
+0.337volt
- (b)
-0.337volt
- (c)
0.674 volt
- (d)
-0.674volt
When a copper wire is immersed in silver nitrate solution ,the colour of the solution becomes blue,because copper
- (a)
Oxidises silver into silver ions
- (b)
reduces silver ions in the solution
- (c)
is reduced to copper(i)
- (d)
is oxidised to copper(i)
At infinite dilution ,the molar conductivity in 5 cm2 mol-1 units for various electrolytes is given as HCl =426,NaCl=126,CH3COONa=91.From these data ,the calculated value of molar conductivity at infinite dilution for CH3COOH will be
- (a)
391
- (b)
335
- (c)
300
- (d)
217
The correct order of equivalent conductance at infinite dilution of LiCl,NaCl and KCl is
- (a)
LiCl>NaCl>KCl
- (b)
KCl>NaCl>LiCl
- (c)
NaCl>KCl>LiCl
- (d)
LiCl>KCl>NaCl
The amount of aluminium metal deposited when 0.1F electricity is passed through aluminium chloride solution is
- (a)
0.27g
- (b)
0.3g
- (c)
0.9g
- (d)
0.18g
The charge in coulombs of N-3 ion is
- (a)
\(96500\)
- (b)
\(4.8\times10^{19}\)
- (c)
\(4.8\times10^{-10}\)
- (d)
\(1.6\times10^{-19}\)
The unit of electrochemical equivalent is
- (a)
coulomb g-1
- (b)
g-ampere
- (c)
g ampere-1
- (d)
g coulomb-1
How many coulombs of electricity are required to reduce 1 mol of MnO-4 to Mn2+?
- (a)
\(4.825\times10^5 c\)
- (b)
\(8.825\times10^5 c\)
- (c)
\(12.825\times10^5 c\)
- (d)
NONE OF THE ABOVE
The e.m.f of the cell formed by E0 Fe2+/Fe=-0.45 v would be approximately
- (a)
0.25 v
- (b)
0.22 v
- (c)
0.26 v
- (d)
None of the above
The standard reduction potentials of Sn2+/Sn,Zn2+/Zn,Fe2+/Fe are respectively -0.14 v,-0.76v and -0.44 v. pick out the correct statement
- (a)
Corrosion of tin can be prevented by coating with Zinc
- (b)
Corrosion of zinc can be prevented by coating with tin
- (c)
Corrosion of zinc can be prevented by coating with Fe
- (d)
Corrosion of iron can be prevented by coating with tin
The standard reduction potentials are Cu2+/Cu=+0.34 v;Hg2+ /Hg =+0.80 v;Zn2+/Zn=-0.76 v pick out the correct statement.
- (a)
Cu reduces Zn2+
- (b)
Cu reduces Hg2+
- (c)
Hg reduces Cu2+
- (d)
Zinc reduces Cu2+
The best electrical conductor among the following is
- (a)
0.01 M NaCl
- (b)
0.10 M ethanol
- (c)
0.10 M CH3COOH
- (d)
0.10 M sucrose
If \(\phi\) denotes reduction potential,then which is true
- (a)
E0 cell=\(\phi\) right-\(\phi\) left
- (b)
E0 cell=\(\phi\) left+\(\phi\) right
- (c)
E0 cell=\(\phi\) left-\(\phi\) right
- (d)
E0 cell=(\(\phi\) left-\(\phi\) right)
What will be the emf for the given cell? Pt|H2(P1)|H+ (aq) || H2(P2) Pt
- (a)
\(\frac{RT}{F} log \frac{P_1}{p_2}\)
- (b)
\(\frac{RT}{2F} log \frac{P_1}{p_2}\)
- (c)
\(\frac{RT}{P} log \frac{P_1}{p_2}\)
- (d)
NONE OF THESE
What is the emf of the cell? Cr|Cr3+(1.0 M) || Cq2+(1.0M)||Cq2+ (0.1M)|Cq (E0 for Cr3+|Cr =-0.74 volt and E0 for Co2+/Co=-0.28 volt)
- (a)
-1.02 volt
- (b)
-0.46 volt
- (c)
+0.46 volt
- (d)
1.66 volt
In a lead storage battery the reaction that occurs at anode during discharge is
- (a)
\(Pb+SO_4^{2-}\longrightarrow PbSO_4+2e\)
- (b)
\(PbO_2+4H^+SO\ ^{2-}_4+2e\longrightarrow PbSO_4+2H_2O\)
- (c)
\(PbSO_4+2e\longrightarrow Pb+SO_4^{2-}\)
- (d)
\(PbSO_4+2H_2O\longrightarrow PbO_2+SO_4^{2-}+4H^++2e\)
The cell constant of a conductivity cell
- (a)
changes with change of electrolyte
- (b)
change with change of concentration of electrolyte
- (c)
changes with temperature of electrolyte
- (d)
remains constant for a cell
Match the following and choose the correct option.
Column I (Properties) |
Column II (Units) |
A. Cell constant |
p. \({ \Omega }^{ -1 }{ cm }^{ 2 }{ eq }^{ -1 }\) |
B. Molar conductance | q. cm-1 or m-1 |
C. Equivalent conductance | r. S cm2 mol-1 |
D. Specific conductance | s. mho cm -1 |
- (a)
A B C D q r p s - (b)
A B C D r p p s - (c)
A B C D q q r s - (d)
A B C D r q p s
The equivalent conductivity of a solution containing 2.54 g of Cu SO4 per L is \(91.0{ \quad \Omega }^{ -1 }{ cm }^{ 2 }{ eq }^{ -1 }\). Its conductivity would be
- (a)
\(2.9\times { 10 }^{ -3 }{ \quad \Omega }^{ -1 }{ cm }^{ -1 }\)
- (b)
\(1.9\times { 10 }^{ -3 }{ \quad \Omega }^{ -1 }{ cm }^{ -1 }\)
- (c)
\(2.4\times { 10 }^{ -3 }{ \quad \Omega }^{ -1 }{ cm }^{ -1 }\)
- (d)
\(3.6\times { 10 }^{ -3 }{ \quad \Omega }^{ -1 }{ cm }^{ -1 }\)
The standard potential of a cell using the reaction, \({ 2MnO }_{ 4 }^{ - }(aq)+3Hg(l)+{ H }_{ 2 }O\rightleftharpoons 2MnO_{ 2 }(s)+3HgO(s)+2OH(aq)\)is 0.489 V at \({ 25 }^{ \circ }C\) . What is the equilibrium constant of the reaction?
- (a)
3.631 \(\times\) 1049
- (b)
3.631 \(\times\) 10-49
- (c)
4.831 \(\times\) 1027
- (d)
4.831 \(\times\) 10-27
Given, The value of standard electrode potential for the change, Fe3+(aq)+e- \(\longrightarrow \) Fe2+(aq) will be
- (a)
-0.072 V
- (b)
0.385 V
- (c)
0.770 V
- (d)
-0.270 V