Hòa tan hoàn toàn a mol Al2O3 vào dung dịch chứa 2a mol Ba(OH)2...

Sau khi hòa tan a mol Al2​O3​ vào 2a mol Ba(OH)2​:
$\begin{aligned}
& A{{l}_{2}}{{O}_{3}}+Ba{{\left( OH \right)}_{2}}\xrightarrow{{}}Ba{{\left( Al{{O}_{2}} \right)}_{2}}+{{H}_{2}}O \\
& \to X\left\{ \begin{aligned}
& Ba{{\left( Al{{O}_{2}} \right)}_{2}}:a \\
& Ba{{\left( OH \right)}_{2}}:a \\
\end{aligned} \right. \\
\end{aligned}$
+ Vậy số chất có thể tác dụng với dung dịch X gồm:
CO2​, Fe(NO3​)2​, NH4​Cl, NaHCO3​, HCl, Al và Na2​CO3​
Các phương trình phản ứng:
$\begin{aligned}
& C{{O}_{2}}+Ba{{\left( OH \right)}_{2}}\xrightarrow{{}}BaC{{O}_{3}}\downarrow +{{H}_{2}}O \\
& C{{O}_{2}}+{{H}_{2}}O+Ba{{\left( Al{{O}_{2}} \right)}_{2}}\xrightarrow{{}}Ba{{\left( HC{{O}_{3}} \right)}_{2}}+Al{{\left( OH \right)}_{3}}\downarrow \\
& Fe{{\left( N{{O}_{3}} \right)}_{2}}+Ba{{\left( OH \right)}_{2}}\xrightarrow{{}}Fe{{\left( OH \right)}_{2}}+Ba{{\left( N{{O}_{3}} \right)}_{2}} \\
& N{{H}_{4}}Cl+Ba{{\left( OH \right)}_{2}}\xrightarrow{{}}BaC{{l}_{2}}+N{{H}_{3}}\uparrow +{{H}_{2}}O \\
& 2N{{H}_{4}}Cl+2{{H}_{2}}O+Ba{{\left( Al{{O}_{2}} \right)}_{2}}\xrightarrow{{}}2N{{H}_{3}}+2Al{{\left( OH \right)}_{3}}+BaC{{l}_{2}} \\
& 2NaHC{{O}_{3}}+Ba{{\left( OH \right)}_{2}}\xrightarrow{{}}BaC{{O}_{3}}\downarrow +N{{a}_{2}}C{{O}_{3}} \left( hoc NaOH \right)+2{{H}_{2}}O \\
& HCl+Ba{{\left( OH \right)}_{2}}\xrightarrow{{}}BaC{{l}_{2}}+{{H}_{2}}O \\
& 2HCl+2{{H}_{2}}O+Ba{{\left( Al{{O}_{2}} \right)}_{2}}\xrightarrow{{}}BaC{{l}_{2}}+2Al{{\left( OH \right)}_{3}} \\
& 2Al+2{{H}_{2}}O+Ba{{\left( OH \right)}_{2}}\xrightarrow{{}}Ba{{\left( Al{{O}_{2}} \right)}_{2}}+3{{H}_{2}} \\
& N{{a}_{2}}C{{O}_{3}}+Ba{{\left( OH \right)}_{2}}\xrightarrow{{}}BaC{{O}_{3}}\downarrow +2NaCl \\
& N{{a}_{2}}C{{O}_{3}}+Ba{{\left( Al{{O}_{2}} \right)}_{2}}\xrightarrow{{}}2NaAl{{O}_{2}}+BaC{{O}_{3}} \\
\end{aligned}$