Hấp thụ hoàn toàn 1,568 lít CO2 (đktc) vào 500 ml dung dịch NaOH 0,16M

* Hướng dẫn giải

Đáp án A

$$\begin{gathered} C{O}_2:0,07 \mathrm{mol}+\left\{\begin{array}{l}NaOH:0,08\mathrm{mol}\\ \mathrm{Ba}(\mathrm{OH}{)}_2:0,25\mathrm{a} \mathrm{mol}\\ {\mathrm{BaCl}}_2:0,04 \mathrm{mol}\end{array}\right.\to \left\{\begin{array}{l}BaC{O}_3\downarrow :0,02\mathrm{mol}\\ dung dịch Z\end{array}\right. \\ Z\left\{\begin{array}{c}N{a}^{+} \stackrel{BTNT.Na}{\to }{n}_{N{a}^{+}}=n_{NaOH}=0,08 \mathrm{mol}\\ C{l}^{-} \stackrel{BTNT.Cl}{\to }{n}_{C{l}^{-}}=2n_{BaC{l}_2}=0,08\mathrm{mol}\\ B{a}^{2+}\stackrel{BTNT.Ba}{\to }{n}_{B{a}^{2+}}=n_{\mathrm{Ba}(\mathrm{OH}{)}_2}+n_{BaC{l}_2}=(0,02+0,25a) \mathrm{mol}\\ HC{O}_3^{-} \stackrel{BTNT.C}{\to }{n}_{HC{O}_3^{-}}=0,05 \mathrm{mol}\end{array}\right. \\ \stackrel{BTNT\mathrm{choZ}}{\to }2(0,02+0,25a)=0,05\to a=0,02 \end{gathered}$$