Chemical & Ionic Equilibrium · JEE Main previous year questions

2006 4 questions

1. Q1092006 · 29 Apr 2006 · Shift 1

   Phosphorus pentachloride dissociates as follows, in a closed reaction vessel $$\mathrm{PC}{\mathrm{l}}_5(\mathrm{g})\rightleftharpoons \mathrm{PC}{\mathrm{l}}_3(\mathrm{g})+\mathrm{C}{\mathrm{l}}_2(\mathrm{g})$$ If total pressure at equilibrium of the reaction mixture is P and degree of dissociation of $\mathrm{PC}{\mathrm{l}}_5$ is x, the partial pressure of $\mathrm{PC}{\mathrm{l}}_3$ will be

   1. A.$(\frac{x}{x+1})P$
   2. B.$(\frac{2x}{1-x})P$
   3. C.$(\frac{x}{x-1})P$
   4. D.$(\frac{x}{1-x})P$
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   Answer: A

2. Q1102006 · 29 Apr 2006 · Shift 1

   The equilibrium constant for the reaction $$\mathrm{S}{\mathrm{O}}_3(\mathrm{g})\rightleftharpoons \mathrm{S}{\mathrm{O}}_2(\mathrm{g})+\frac{1}{2}{\mathrm{O}}_2(\mathrm{g})$$ is ${\mathrm{K}}_{\mathrm{c}}=4.9\times 10^{-2}$. The value of ${\mathrm{K}}_{\mathrm{c}}$ for the reaction $$2S{\mathrm{O}}_2(\mathrm{g})+{\mathrm{O}}_2(\mathrm{g})\rightleftharpoons 2S{\mathrm{O}}_3(\mathrm{g})$$ will be :

   1. A.416
   2. B.$9.8\times 10^{-2}$
   3. C.$4.9\times 10^{-2}$
   4. D.$2.40\times 10^{-3}$
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   Answer: A

3. Q1112006 · 29 Apr 2006 · Shift 1

   Given the data at $25^{\circ }\mathrm{C}$, $$\mathrm{Ag}+{\mathrm{I}}^{-}\to \mathrm{AgI}+{\mathrm{e}}^{-},{\mathrm{E}}^{\mathrm{o}}=0.152\mathrm{V}$$ $$\mathrm{Ag}\to \mathrm{A}{\mathrm{g}}^{+}+{\mathrm{e}}^{-},{\mathrm{E}}^{\mathrm{o}}=-0.800\mathrm{V}$$ What is the value of $\log {\mathrm{K}}_{\mathrm{sp}}$ for AgI? ($2.303RT/F=0.059\mathrm{V}$)

   1. A.$-8.12$
   2. B.$+8.612$
   3. C.$-37.83$
   4. D.$-16.13$
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   Answer: D

4. Q1452006 · 29 Apr 2006 · Shift 1

   The correct order of increasing acid strength of the compounds (A) $\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{O}}_2\mathrm{H}$ (B) $\mathrm{MeOC}{\mathrm{H}}_2\mathrm{C}{\mathrm{O}}_2\mathrm{H}$ (C) $\mathrm{C}{\mathrm{F}}_3\mathrm{C}{\mathrm{O}}_2\mathrm{H}$ (D) $\mathrm{M}{\mathrm{e}}_2\mathrm{CH}-\mathrm{C}{\mathrm{O}}_2\mathrm{H}$

   1. A.$D<A<B<C$
   2. B.$A<D<B<C$
   3. C.$B<D<A<C$
   4. D.$D<A<C<B$
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   Answer: A