A solution of Ni(NO3)2 is electrolysed between platinum electrodes using a current of 5 amperes for 20 minutes. What mass of Ni is deposited at the cathode?
1.82 g
1.95 g
2.01 g
1.16 g
The resistance of a cell containing 0.001M KCl solution at 298 K is 1500 Ω. The conductivity is 0.146 × 10–3 S cm–1. The cell constant would be-
1. 0.12 cm-1
2. 0.56 cm-1
3. 0.22 cm-1
4. 1.36 cm-1
The number of Faradays required to produce 20.0 g of Ca from molten CaCl2 is-
2F
1F
4F
3F
Three electrolytic cells A, B, C containing solutions of ZnSO4, AgNO3, and CuSO4, respectively are connected in series. A steady current of 1.5 amperes was passed through them until 1.45 g of silver was deposited at the cathode of cell B. The current flow time is-
14 minutes
25 minutes
20 minutes
11 minutes
If a current of 0.5 ampere flows through a metallic wire for 2 hours, then how many electrons would flow through the wire?
1. 2.35 × 10-222. 2.25 × 10223. 1.34 × 10214. 3.16 × 1024
What is the quantity of electricity in coulombs needed to reduce 1 mol of Cr2O72-? Consider the reaction: Cr2O72- + 14H+ + 6e- → 2Cr+3 + 7H2O
578992 C
289461 C
192974 C
96487 C
What is the potential of hydrogen electrode in contact with a solution whose pH is 10?
0.591 V
-0.591 V
0.295 V
-0.295 V
What will be the emf of the cell in which the following reaction takes place? Given Ecell° = 1.05 V
Ni(s)+2Ag+(0.002 M) →Ni2+(0.160 M) + 2Ag(s)
0.80 V
0.91 V
0.45 V
0.36 V
The cell in which the following reactions occurs:
2Fe3+(aq)+2I-(aq)→2Fe2+(aq)+I2(s) has Ecell⊝= 0.236 V at 298 K.
The equilibrium constant of the cell reaction is :
1. 9.57 × 1072. 8.43 × 1063. 3.68 × 10-74. 1.74 × 105
The correct statement about the given galvanic cell equation is -
Zn(s) + 2Ag+(aq) → Zn2+(aq) + 2Ag(s)
The current will flow from silver to zinc in the external circuit.
The current will flow from zinc to silver in the external circuit.
The current will flow from silver to zinc in the internal circuit.
The current will flow from zinc to silver in the internal circuit.
The molar conductivity of 0.025 mol L−1 methanoic acid is 46.1 S cm2 mol−1.
What is the dissociation constant of methanoic acid? Given λ°(H+)= 349.6 S cm2 mol−1 and λ°(HCOO−) = 54.6 S cm2 mol-1
1. 2.43 × 104 mol L-12. 1.15 × 10-5 mol L-13. 3.67 × 10-4 mol L-14. 2.44 × 10-6 mol L-1
The cell that will measure the standard electrode potential of a copper electrode is :
Pt (s) | H2(g, 0.1 bar) | H+(aq., 1M) || Cu2+(aq, 1 M)| Cu
Electrode potential for Mg electrode varies according to the equation .EMg2+| Mg=EMg2+|Mg0-0.0592log1Mg2+ .
The graph of EMg2+ / Mg vs log [Mg2+] among the following is -
The correct statement among the following options is:
Ecell and ∆rG of cell reaction both are extensive properties.
Ecell and ∆rG of cell reaction both are intensive properties.
Ecell is an intensive property while ∆rG of cell reaction is an extensive property.
Ecell is an extensive property while ∆rG of cell reaction is an intensive property.
The difference between the electrode potentials of two electrodes when no current is drawn through the cell is called :
Cell potential.
Cell emf.
Potential difference.
Cell voltage.
The incorrect statement about an inert electrode in a cell is :
It does not participate in the cell reaction.
It provides surface neither for oxidation or for the reduction reaction.
It provides a surface for the conduction of electrons.
It provides a surface for redox reaction.
An electrochemical cell can behave like an electrolytic cell when -
Ecell > Eext
Eext > Ecell
Ecell = Eext
Ecell =O
The incorrect statement about the solution of electrolytes is :
Conductivity of solution depends upon the size of ions.
Conductivity depends upon the viscosity of solution.
Conductivity does not depend upon the solvation of ions present in solution.
Conductivity of solution increases with temperature.
ECr2O72-/Cr3+⊝=1.33V ; ECl2/Cl-⊖=1.36VEMnO4-/Mn2+⊝=1.51V ; ECr3+/Cr⊖=-0.74V
Use the data give above, the most stable oxidized species is :
Cr3+
MnO4-
Cr2O72-
Mn2+
The quantity of charge required to obtain one mole of aluminium from Al2O3 is :
1 F
6 F
3 F
2 F
The cell constant of a conductivity cell-
Changes with the change of electrolyte.
Changes with the change of concentration of electrolyte.
Changes with the temperature of the electrolyte.
Remains constant for a cell.
Correct statement about charging of the lead storage battery is -
PbSO4 anode is reduced to Pb
PbSO4 cathode is reduced to Pb
PbSO4 cathode is oxidised to Pb
PbSO4 anode is oxidised to PbO2
Λm°NH4OH is equal to -
Λ°°mNH4OH+Λ°mNH4Cl-Λ°(HCl)
Λ°mNH4Cl+Λ°m(NaOH)-Λ°(NaCI)
ΛmNH4Cl0+Λm(NaCl)0-Λ0NaOH
Λm(NaOH)°+Λm(NaCl)°-Λ°NH4Cl
In the electrolysis of concentrated aqueous sodium chloride solution, the half cell reaction will occur at the anode is :
Na+aq+e-⟶Nas ; Ecell⊖=-2.71V
2H2Ol⟶O2 g+4H+aq+4e- ; E°cell=1.23V
H+aq+e-⟶12H2 g ; Ecell °=0.00V
Cl-aq⟶12Cl2g+e- ; Ecell°=1.36V
Match the terms given in Column I with the items given in Column II.
Column I
Column II
A. Λm
B. Eocell
C. κ
D. ∆rGcell
1. Intensive property
2. Depends on number of ions/volume
3. Extensive property
4. Increases with dilution
Codes
A B C D
2 3 4 1
1 2 3 5
5 4 3 2
4 1 2 3
Assertion: Current stops flowing when Ecell = 0.
Reason: Equilibrium of the cell reaction is attained.
Both assertion and reason are true and the reason is the correct explanation of assertion.
Both assertion and reason are true and the reason is not the correct explanation of assertion.
Assertion is true but the reason is false.
Both assertion and reason are false.
Assertion: Copper sulphate can be stored in a zinc vessel.
Reason: Zinc is less reactive than copper.
In a typical fuel cell, the reactants (R) and product (P) are :-
R=H2(g), O2(g); P=H2O2(l)
R=H2(g), O2(g); P=H2O(l)
R=H2(g), O2(g), Cl2(g); P=HClO4(aq)
R=H2(g), N2(g); P=NH3(aq)
The Gibb's energy for the decomposition of Al2O3 at 500°C is as follows:
23Al2O3→43Al + O2;∆rG = +960 kJ mol-1
The potential difference needed for the electrolytic reduction of aluminium oxide(Al2O3) at 500°C is at least,
3.0 V
2.5 V
5.0 V
4.5 V
Molar conductivities (∧°m) at infinite dilution of NaCl, HCl and CH3COONa are 126.4, 425.9 and 91.0 S cm2 mol-1 respectively. (∧°m) for CH3COOH will be:
180.5 S cm2mol-1
290.8 S cm2mol-1
390.5 S cm2mol-1
425.5 S cm2mol-1
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