Hấp thụ hết x lít CO2 ở đktc vào một dung dịch chứa 0,4mol KOH

* Hướng dẫn giải

Đáp án A

$C{O}_2+\left\{\begin{array}{l}\underset{0,4mol}{\underbrace{KOH}}:\\ \underset{0,3mol}{\underbrace{NaOH}}\\ \underset{0,4mol}{\underbrace{K_{2}C{O}_3}}\end{array}\right.\to Y\left\{\begin{array}{l}\begin{array}{c}{K}^{+}\stackrel{BTNT.K}{\to }{n}_{K^{+}}=1,2 \mathrm{mol}\\ {\mathrm{Na}}^{+}\stackrel{\mathrm{BTNT}.\mathrm{Na}}{\to }{\mathrm{n}}_{{\mathrm{Na}}^{+}}=0,3 \mathrm{mol}\\ {\mathrm{CO}}_3^{2-}:a \mathrm{mol}\end{array}\\ {\mathrm{HCO}}_3^{-}:b \mathrm{mol}\end{array}\right.\stackrel{+BaC{l}_2 \mathrm{d}-}{\to }\underset{0,2 \mathrm{mol}}{\underbrace{BaC{O}_3\downarrow }}$

$$\begin{gathered} \to \left\{\begin{array}{l}\stackrel{\mathrm{BTNTchoY}}{\to }2a + b = 1,5\\ n_{C{O}_3^{2-}}=n_{BaC{O}_3}\to a=0,2\end{array}\right.\to \left\{\begin{array}{l}a=0,2\\ b=1,1\end{array}\right. \\ \stackrel{BTNT.C}{\to }{n}_{C{O}_2}+0,4=0,2+1,1\to n_{C{O}_2}=0,9 \mathrm{mol}\to \mathrm{x}=22,4.0,9=20,16 lít \end{gathered}$$