Chemistry - Chemical Kinetics Question with Solution | TestHub

Question Explanation:

Temperature dependence of conductivity in crystals with Frenkel defects.

Concept:

Frenkel defect thermodynamics, Arrhenius equation for conductivity.

Solution:

1. In Frenkel defects $n=\sqrt{N{N}_i}{\exp }^{\left(-\Delta H_f/2RT\right)}$ where Ni is interstitial sites. (B) is Correct.

2. Conductivity σ=nqμ. Mobility μ ∝ e ^{−ΔHm /RT}

3. $\sigma \propto e-\frac{\Delta {\mathrm{H}}_{\mathrm{f}})}{2\mathrm{RT}}.e\frac{{}^{-\Delta {\mathrm{H}}_{\mathrm{m}}}}{RT}=e-\frac{\left(\Delta {\mathrm{H}}_{\mathrm{f}}/2+\Delta {\mathrm{H}}_{\mathrm{m}}\right)}{\mathrm{RT}}$ (A) is Correct .

4. Frenkel defects do not change volume significantly, so pressure has a much smaller effect compared to Schottky defects. However, since AgCl is a low-coordination lattice, (4) is Correct. Final Answer: (A, B, D)