Q56.Consider the following cell reaction Cd(s) + Hg2 SO4( s) + 95 H2O(l) ⇌CdSO4 ⋅95 H2O(s) + 2 Hg(l). The value of E0cell is 4. 315 V at 25°C. If ΔH°= −825. 2 kJ mol−1, the standard entropy change ΔS° in J K−1 is _________ . (Nearest integer) [Given : Faraday constant = 96487 C mol−1 ]
What This Question Tests
This is a multi-concept question that links standard cell potential (E°cell) to Gibbs free energy (ΔG°) and then uses the thermodynamic relationship between ΔG°, ΔH°, and ΔS° to find the standard entropy change.
Concepts Tested
Formulas Used
ΔG° = -nFE°cell
ΔG° = ΔH° - TΔS°
📚 NCERT Sections This Tests
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.
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.
📋 Question Details
- Chapter
- Electrochemistry
- Topic
- Relationship between E°cell, ΔH°, and ΔS°
- Year
- 2021
- Shift
- 31 Aug Shift 1
- Q Number
- Q56
- Type
- Numerical
- NCERT Ref
- Class 12 Chemistry Ch 3: Electrochemistry
More from this Chapter
Q58.The mass of product liberated on anode in an electrochemical cell depends on (where t is the time period, for which the current is passed) (1) (It)1/2 (2) IT (3) I/t (4) I2t
Q48.The negative Zn pole of a Daniell cell, sending a constant current through a circuit, decreases in mass by 0.13 g in 30 minutes. If the electrochemical equivalent of Zn and Cu are 32.5 and 31.5 respectively, the increase in the mass of the positive Cu pole in this time is (1) 0.180 g (2) 0.141 g (3) 0.126 g (4) 0.242 g
Q49.The electrochemical equivalent of a metal is 3.3 × 10−7 kg per coulomb. The mass of the metal liberated at the cathode when a 3 A current is passed for 2 seconds will be (1) 19.8 × 10−7 kg (2) 9.9 × 10−7 kg (3) 6.6 × 10−7 kg (4) 1.1 × 10−7 kg
Q46.Two voltameters one of copper and another of silver, are joined in parallel. When a total charge q flows through the voltameters, equal amount of metals are deposited. If the electrochemical equivalents of copper and silver are z1 and z2 respectively the charge which flows through the silver voltameter is (1) q z1 (2) q z2 1+ 1+ z2 z1 (3) q z1 (4) q z2 z2 z1