Đáp án đúng: D
500 ml và 59,1 (g).
$\begin{array}{l}{{\text{n}}_{\text{BaC}{{\text{O}}_{\text{3}}}}}\,\text{=}\,\text{0}\text{,1}\,\text{mol;}\,{{\text{n}}_{\text{HCO}_{\text{3}}^{\text{-}}}}\,\text{=}\,{{\text{n}}_{\text{C}{{\text{O}}_{\text{2}}}}}\,\text{-}\,{{\text{n}}_{\text{CO}_{\text{3}}^{\text{2-}}}}\,\text{=}\,\text{0}\text{,3}\,\text{mol}\\{{\text{n}}_{\text{Ba(OH}{{\text{)}}_{\text{2}}}}}\,\text{=}\,{{\text{n}}_{\text{CO}_{\text{3}}^{\text{2-}}}}\,\text{+}\,\frac{{{\text{n}}_{\text{HCO}_{\text{3}}^{\text{-}}}}}{\text{2}}\,\text{=}\,\text{0}\text{,25}\,\Rightarrow \,\text{V}\,\text{=}\,\text{0}\text{,5}\,\text{lit}\\\xrightarrow{\text{+}\,\text{Ba(OH}{{\text{)}}_{\text{2}}}}\,{{\text{n}}_{\text{BaC}{{\text{O}}_{\text{3}}}}}\,\text{=}\,{{\text{n}}_{\text{HCO}_{\text{3}}^{\text{-}}\,\text{(1)}}}\text{=}\,\text{0}\text{,3}\,\text{mol}\,\Rightarrow \,\text{m}\,\text{=}\,{{\text{m}}_{\text{BaC}{{\text{O}}_{\text{3}}}}}\,\text{=}\,\text{59}\text{,1}\,\text{gam}\end{array}$
