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The Gibbs energy for the decomposition of Al_2 O_3 at 500° C is as follows : 2 3 Al_2 O_3 → 4 3 Al+ O_2, Δ_ G=+966 ~kJ ~mol^-1 The potential…

JEE Main 2010 — Chemistry Physical Chemistry

2010mcqmedium

The Gibbs energy for the decomposition of Al2O3\mathrm{Al}_2 \mathrm{O}_3Al2​O3​ at 500∘C500^{\circ} \mathrm{C}500∘C is as follows : 23Al2O3→43Al+O2,ΔrG=+966 kJ mol−1\frac{2}{3} \mathrm{Al}_2 \mathrm{O}_3 \rightarrow \frac{4}{3} \mathrm{Al}+\mathrm{O}_2, \Delta_{\mathrm{r}} \mathrm{G}=+966 \mathrm{~kJ} \mathrm{~mol}^{-1}32​Al2​O3​→34​Al+O2​,Δr​G=+966 kJ mol−1 The potential difference needed for electrolytic reduction of Al2O3\mathrm{Al}_2 \mathrm{O}_3Al2​O3​ at 500∘C500^{\circ} \mathrm{C}500∘C is at least

Official previous-year question

Held on 30 Apr 2010 · Verified 6 Jul 2026.

Options

  1. A

    4.5 V4.5 \mathrm{~V}4.5 V

  2. B

    3.0 V3.0 \mathrm{~V}3.0 V

  3. C

    2.5 V2.5 \mathrm{~V}2.5 V

  4. D

    5.0 V5.0 \mathrm{~V}5.0 V

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