Đáp án đúng: A
28,41% và 71,59%.
$\begin{array}{l}\text{CaC}{{\text{O}}_{\text{3}}}\,\xrightarrow{{{\text{t}}^{\text{o}}}}\,\text{CaO}\,\text{+}\,\text{C}{{\text{O}}_{\text{2}}}\\\text{x}\,\text{mol}\,\,\,\,\,\,\,\xrightarrow{{}}\,\,\,\,\,\,\,\,\,\,\,\,\,\text{x}\,\text{mol}\\\text{MgC}{{\text{O}}_{\text{3}}}\,\xrightarrow{{{\text{t}}^{\text{o}}}}\,\text{MgO}\,\text{+}\,\text{C}{{\text{O}}_{\text{2}}}\\\text{y}\,\text{mol}\,\,\,\,\,\,\,\,\,\,\xrightarrow{{}}\,\,\,\,\,\,\,\,\,\,\,\,\,\text{y}\,\text{mol}\\{{\text{m}}_{\text{CaC}{{\text{O}}_{\text{3}}}\,\text{+}\,\text{MgC}{{\text{O}}_{\text{3}}}}}\,\text{=}\,\text{2}{{\text{m}}_{\text{C}{{\text{O}}_{\text{2}}}}}\Rightarrow \text{100x}\,\text{+}\,\text{84y}\,\text{=}\,\text{2}\text{.44}\text{.(x+y)}\,\\\Rightarrow \,\frac{\text{x}}{\text{y}}\,\text{=}\,\frac{\text{88-84}}{\text{100-88}}\,\text{=}\,\frac{\text{1}}{\text{3}}\\\Rightarrow {\scriptstyle{}^{\text{o}}\!\!\diagup\!\!{}_{\text{o}}\;}\text{CaC}{{\text{O}}_{\text{3}}}\,\text{=}\,\frac{\text{100}\text{.1}}{\text{100}\text{.1+84}\text{.3}}\,\text{.100}{\scriptstyle{}^{\text{o}}\!\!\diagup\!\!{}_{\text{o}}\;}\text{=}\,\text{28,4}{\scriptstyle{}^{\text{o}}\!\!\diagup\!\!{}_{\text{o}}\;}\end{array}$
