Đáp án đúng: D
0,3M.
$\begin{array}{l}\text{KLK}\,\,\text{R}\,\xrightarrow{\text{HCl}\,\text{+}\,{{\text{H}}_{\text{2}}}\text{O}}\,\text{RCl}\,\text{+}\,\text{ROH}\,\text{+}\frac{\text{1}}{\text{2}}{{\text{H}}_{\text{2}}}\\\Rightarrow \,{{\text{n}}_{\text{HCl}}}\text{+}{{\text{n}}_{{{\text{H}}_{\text{2}}}\text{O}\,}}\text{=}{{\text{n}}_{\text{RCl}}}\,\text{+}\,{{\text{n}}_{\text{O}{{\text{H}}^{\text{-}}}}}\,\text{=}\,\text{2}{{\text{n}}_{{{\text{H}}_{\text{2}}}}}\,\text{=}\,\text{0,25}\\\text{ROH}\,\,\,\text{+}\,\,{{\text{H}}^{\text{+}}}\,\xrightarrow{{}}\,{{\text{R}}^{\text{+}}}\,\text{+}\,{{\text{H}}_{\text{2}}}\text{O}\\\text{0,04}\,\leftarrow \,\text{0,04}\\\text{A}{{\text{l}}^{\text{3+}}}\,\text{+}\,\,\text{3O}{{\text{H}}^{\text{-}}}\,\xrightarrow{{}}\,\text{Al(OH}{{\text{)}}_{\text{3}}}\\\text{0,02}\,\,\,\,\,\text{0,06}\,\,\,\,\xleftarrow{{}}\,\,\,\,\,\text{0,02}\\\Rightarrow {{\text{n}}_{\text{O}{{\text{H}}^{\text{-}}}}}\text{=}\,\text{0,1}\,\Rightarrow \,{{\text{n}}_{\text{HCl}\,}}\text{=}\,\text{0,15}\,\Rightarrow \,{{\text{C}}_{\text{M}\,\,\text{HCl}}}\,\text{=}\,\text{0,3}\,\text{M}\end{array}$
