Chemical Thermodynamics · JEE Main previous year questions

2015 2 questions

1. Q642015 · 4 Apr 2015 · Shift 1

   The standard Gibbs energy change at $300\mathrm{K}$ for the reaction $2\mathrm{A}\rightleftharpoons \mathrm{B}+\mathrm{C}$ is $2494.2\mathrm{J}$. At a given time, the composition of the reaction mixture is $[\mathrm{A}]=1/2$, $[\mathrm{B}]=2$ and $[\mathrm{C}]=1/2$. The reaction proceeds in the: $[R=8.314J/K/mol,e=2.718]$

   1. A.reverse direction because $\mathrm{Q}>{\mathrm{K}}_{\mathrm{c}}$
   2. B.forward direction because $\mathrm{Q}<{\mathrm{K}}_{\mathrm{c}}$
   3. C.reverse direction because $\mathrm{Q}<{\mathrm{K}}_{\mathrm{c}}$
   4. D.forward direction because $\mathrm{Q}>{\mathrm{K}}_{\mathrm{c}}$
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   Answer: A

2. Q832015 · 4 Apr 2015 · Shift 1

   Which one of the following alkaline earth metal sulphates has its hydration enthalpy greater than its lattice enthalpy?

   1. A.$\mathrm{BeS}{\mathrm{O}}_4$
   2. B.$\mathrm{BaS}{\mathrm{O}}_4$
   3. C.$\mathrm{SrS}{\mathrm{O}}_4$
   4. D.$\mathrm{CaS}{\mathrm{O}}_4$
   Show answer

   Answer: A