The reaction

${\mathrm{CaCO}}_3\left(\mathrm{s}\right)\rightleftharpoons \mathrm{CaO}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)$

is in equilibrium in a closed vessel at $298 \mathrm{K}.$ The partial pressure (in atm) of ${\mathrm{CO}}_2\left(\mathrm{g}\right)$ in the reaction vessel is closest to:

[Given: The change in Gibbs energies of formation at $298 \mathrm{K}$ and $1$ bar for

$\mathrm{CaO}\left(\mathrm{s}\right)=-603.501 \mathrm{kJ} {\mathrm{mol}}^{-1}$

${\mathrm{CO}}_2\left(\mathrm{g}\right)=-394.389 \mathrm{kJ} {\mathrm{mol}}^{-1}$

${\mathrm{CaCO}}_3\left(\mathrm{s}\right)=-1128.79 \mathrm{kJ} {\mathrm{mol}}^{-1}$

Gas constant $\mathrm{R}=8.314 \mathrm{J} {\mathrm{K}}^{-1} {\mathrm{mol}}^{-1}$]

• Correct answer
  A

  $1.13\times {10}^{-23}$
• B

  $0.95$
• C

  $1.05$
• D

  $8.79\times {10}^{23}$

Hence, the correct answer is option: 'A'.