Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

6. The cell in which the following reaction occurs:
2Fe³⁺ (aq) + 2I^–(aq) $\to$ 2Fe²⁺ (aq) + I₂(s) has E⁰_cell = 0.236 V at 298 K. Calculate the standerd Gibbs energy and the equilibrium constance of the cell reaction.

Answer:

The cell is
2Fe³⁺ (aq) + 2I^–(aq) $\to$ $2 {Fe}^{2 +} (aq) + I_{2} (s)$
$E^{0} cell = 0.236 {V^{0}}_{a} ∆_{r} G^{0} = - {nFE}^{0}_{cell} = - 2 \times 0.236 \times 96487 C {mol}^{- 1} = - 45541 J = - 45.54 kJ {mol}^{- 1}$

$\log Kc = \frac{{nFE}^{0}_{cell}}{2.303 \times RT} = \frac{2 \times 96487 \times 0.236}{2.303 \times 8.31 \times 298} = \frac{45541.864}{5703.1031} = 7.9854 or Kc = Antilog 7.9854 or Kc = 9.62 \times 10^{7}$

919 Views

Short Answer Type

7. Why does the conductivity of a solution decrease with dilution?

233 Views

8. Suggest a way to determine the Λ°_m value of water.

175 Views

Long Answer Type

9. The molar conductivity of 0.025 mol L^–1methanoic acid is 46.1 S cm² mol^–1. Calculate its degree of dissociation and dissociation constant. Give λ°(H⁺) = 349.6 S cm²mol^–1 and λ° (HCOO^– ) = 54.6 s cm² mol^–1.

225 Views