Hấp thụ hoàn toàn 8,96 lít CO2 (đktc) vào V ml dung dịch chứa NaOH

* Hướng dẫn giải

Đáp án B

$\underset{0,4 \mathrm{mol}}{\underbrace{C{O}_2}}+\left\{\begin{array}{l}NaOH:2,75V \mathrm{mol}\\ {\mathrm{K}}_{2}C{O}_3:V \mathrm{mol}\end{array}\right.\to 4 muối \left\{\begin{array}{l}\begin{array}{c}N{a}^{+} \stackrel{BTNT.Na}{\to }{n}_{N{a}^{+}}=2,75V\mathrm{mol}\\ K^{+}:\stackrel{BTNT.K}{\to }{n}_{K^{+}}=2V \mathrm{mol}\\ C{O}_3^{2-}:a \mathrm{mol}\end{array}\\ HC{O}_3^{-}:b \mathrm{mol}\end{array}\right.$

$\left\{\begin{array}{l}\begin{array}{c}\stackrel{BTNT.C}{\to }0,4 + V = a + b\\ \stackrel{BTNT}{\to }2,75V + 2V = 2a + b\end{array}\\ m_{muối}=23.2,75V+39.2V+60a+61b=64,5\end{array}\right.\to \left\{\begin{array}{l}V=0,2 lít=200\mathrm{ml}\\ a=0,35 \mathrm{mol}\\ b=0,25 \mathrm{mol}\end{array}\right.$