PYQSide ExamsMy practice

Electrochemistry · Question 62

AIPMT 2003MCQEasy📈 Topic in 25% papers+4−1
1

The e.m.f. of a Daniell cell at 298 K is E1. [figure] When the concentration of ZnSO4 is 1.0 M and that of CuSO4 is 0.01 M, the e.m.f. changed to E2. What is the relationship between E1 and E2?

  1. E1 > E2
  2. E1 < E2
  3. E1 = E2
  4. E2 = 0 E1

Answer

(1) E1 > E2

Solution

Cell reaction: Zn + Cu2+ Zn2+ + Cu, n = 2

Nernst equation: Ecell = E cell - 0.0592 [Zn2+][Cu2+]

E1 = E cell - 0.0592 0.011.0

= E cell + 0.059 V

E2 = E cell - 0.0592 1.00.01

= E cell - 0.059 V

E1 > E2

Answer: (1)

AIPMT 2003

Keep practising — Electrochemistry

2

On the basis of the information available from the reaction, 4/3 Al + O2 2/3 Al2O3, G = -827 kJ mol-1 of O2, the minimum e.m.f. required to carry out an electrolysis of Al2O3 is ( F = 96500 C mol-1)

  1. 2.14 V
  2. 4.28 V
  3. 6.42 V
  4. 8.56 V
AIPMT 2003
3

In electrolysis of NaCl when Pt electrode is taken then H2 is liberated at cathode while with Hg cathode it forms sodium amalgam because

  1. Hg is more inert than Pt
  2. more voltage is required to reduce H+ at Hg than at Pt
  3. Na is dissolved in Hg while it does not dissolve in Pt
  4. concentration of H+ ions is larger when Pt electrode is taken
AIPMT 2002
4

Standard electrode potentials are Fe2+/Fe [ E = -0.44 V] and Fe3+/Fe2+ [ E = 0.77 V]; If Fe2+, Fe3+ and Fe blocks are kept together, then

  1. Fe3+ increases
  2. Fe3+ decreases
  3. Fe2+/Fe3+ remains unchanged
  4. Fe2+ decreases.
AIPMT 2001
5

The most convenient method to protect the bottom of ship made of iron is

  1. coating it with red lead oxide
  2. white tin plating
  3. connecting it with Mg block
  4. connecting it with Pb block
AIPMT 2001
6

Cell reaction is spontaneous when

  1. is negative
  2. is positive
  3. E red is positive
  4. E red is negative
AIPMT 2000
7

Ionic conductances of Ba2+ and Cl- ions at infinite dilution are 127 and 76 ohm-1 cm2 mol-1 respectively. Equivalent conductance of BaCl2 at infinite dilution is

  1. 139.5
  2. 101.5
  3. 203
  4. 279
AIPMT 2000
8

For the disproportionation of copper 2Cu+ Cu2+ + Cu, E is (Given E for Cu2+/Cu is 0.34 V and E for Cu2+/Cu+ is 0.15 V.)

  1. 0.49 V
  2. -0.19 V
  3. 0.38 V
  4. -0.38 V
AIPMT 2000

All Electrochemistry PYQs →

PDFDownload Electrochemistry PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters
Physical ChemistrySome Basic Concepts of ChemistryStructure of AtomStates of MatterThermodynamicsEquilibriumRedox ReactionsSolid StateSolutionsElectrochemistryChemical KineticsSurface Chemistry
Inorganic ChemistryClassification of Elements and Periodicity in PropertiesChemical Bonding and Molecular StructureHydrogens-Block Elementsp-Block Elements (Group 13 & 14)Environmental ChemistryGeneral Principles of Isolation of Elementsp-Block Elements (Group 15–18)d- and f-Block ElementsCoordination Compounds
Organic ChemistryOrganic Chemistry – Some Basic Principles and TechniquesIsomerismHydrocarbonsHaloalkanes and HaloarenesAlcohols, Phenols and EthersAldehydes, Ketones and Carboxylic AcidsAminesBiomoleculesPolymersChemistry in Everyday LifePrinciples Related to Practical Chemistry