Question

The partial pressure of carbon monoxide from the following data will be
$CaCO _{3}(s) \xrightleftharpoons{\Delta} CaO (s)+ CO _{2} \uparrow ; K_{p_{1}}=8 \times 10^{-2}$
$CO _{2}(g)+ C (s) \rightleftharpoons 2 CO (g) ; K_{p_{2}}=2$

• A. $0.2 \,atm$
• B. $0.6\, atm$
• C. $0.8\, atm$
• D. $0.4 \,atm$

Answer 1

Answer: (D)

$CaCO _{3}(s) \xrightleftharpoons{\Delta}CaO (s)+ CO _{2} \uparrow ; K_{p_{1}}=8 \times 10^{-2}$
$CO _{2}(g)+ C (s) \longrightarrow 2 CO (g) ; K_{p_{2}}=2$
Thus, for the reaction,
$CaCO _{3}(s)+ C (s) \rightleftharpoons CaO (s)+2 CO (g)$
$ K_{p}^{\prime}=K_{p_{1}} \times K_{p_{2}}=8 \times 10^{-2} \times 2=16 \times 10^{-2}$
$\therefore K_{p}^{\prime}=\left(p_{ CO }(g)\right)^{2}$
$\Rightarrow p_{ CO }=\sqrt{K_{p}^{\prime}}=\sqrt{16 \times 10^{-2}}$
$=4 \times 10^{-1}=0.4\, atm$