Q47.The standard reduction potentials for Zn2+/Zn, Ni2+/Ni, and Fe2+/Fe are −0.76, −0.23 and −0.44 V respectively. The reaction X + Y2+ →X2+ + Y will be spontaneous when: (1) X = Ni, Y = Fe (2) X = Ni, Y = Zn (3) X = Fe, Y = Zn (4) X = Zn, Y = Ni
What This Question Tests
This question tests the ability to determine the spontaneity of a redox reaction by calculating the standard cell potential (E°_cell). For a spontaneous reaction, E°_cell must be positive, implying that the species being oxidized (X) should have a lower reduction potential than the species being reduced (Y).
Concepts Tested
Formulas Used
E°_cell = E°_cathode - E°_anode
ΔG° = -nFE°_cell
📚 NCERT Sections This Tests
2.2 — Given The Standard Electrode Potentials,
Chemistry Class 11 · Chapter 2
2.2 Given the standard electrode potentials, K+/K = –2.93V, Ag+/Ag = 0.80V, Hg2+/Hg = 0.79V Mg2+/Mg = –2.37 V, Cr3+/Cr = – 0.74V Arrange these metals in their increasing order of reducing power.
2.4 — Calculate The Standard Cell Potentials Of Galvanic Cell In Which The Following
Chemistry Class 11 · Chapter 2
2.4 Calculate the standard cell potentials of galvanic cell in which the following reactions take place: (i) 2Cr(s) + 3Cd2+(aq) ® 2Cr3+(aq) + 3Cd (ii) Fe2+(aq) + Ag+(aq) ® Fe3+(aq) + Ag(s) Calculate the DrGo and equilibrium constant of the reactions. 2.5 Write the Nernst equation and emf of the following cells at 298 K: (i) Mg(s)|Mg2+(0.001M)||Cu2+(0.0001 M)|Cu(s) (ii) Fe(s)|Fe2+(0.001M)||H+(1M)|H2(g)(1bar)| Pt(s) (iii) Sn(s)|Sn2+(0.050 M)||H+(0.020 M)|H2(g) (1 bar)|Pt(s) (iv) Pt(s)|Br–(0.010 M)|Br2(l )||H+(0.030 M)| H2(g) (1 bar)|Pt(s).
2.6 — In The Button Cells Widely Used In Watches And Other Devices The Following
Chemistry Class 11 · Chapter 2
2.6 In the button cells widely used in watches and other devices the following reaction takes place: Zn(s) + Ag2O(s) + H2O(l) ® Zn2+(aq) + 2Ag(s) + 2OH–(aq) Determine DrGo and Eo for the reaction.
📋 Question Details
- Chapter
- Electrochemistry
- Topic
- Spontaneity of redox reactions
- Year
- 2012
- Shift
- Offline
- Q Number
- Q47
- Type
- MCQ
- NCERT Ref
- Class 12 Chemistry Ch 3: Electrochemistry
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