Question

A sample of $CaC{O}_{3\left(s\right)}$ is introduced into a sealed container of volume $0.821$ litre and heated to $1000K$ until equilibrium is reached. The equilibrium constant for the reaction $CaC{O}_{3\left(s\right)}\rightleftharpoons Ca{O}_{\left(s\right)}+C{O}_{2\left(g\right)}$ is $4\times {10}^{-2}atm$ at this temperature. Calculate mass of $CaO$ present at equilibrium.

Answer 1

$K_P$ of $C{O}_2=4\times {10}^{-2}$ atm

So, moles of $C{O}_2=$ moles of Ca O

$=\frac{PV}{RT}$

$=\frac{4\times {10}^{-2}\times 0.021}{0.082\times 1000}$

$=0.00040mg$

$\therefore$ mass of Ca O = $0.00040\times 56$

$=22.4mg$