Cho 55,86 gam hỗn hợp X gồm K2CO3, KOH, CaCO3 và Ca(OH)2

* Hướng dẫn giải

Đáp án D

$$\begin{gathered} \begin{array}{l}+ n_{C{O}_2}=0,24 mol; n_{KCl}=0,45 mol.\\ + \underset{X, m_X=55,86 \left(g\right)}{\underbrace{\left\{\begin{array}{l}KOH, K_{2}C{O}_3\\ Ca(OH{)}_2, CaC{O}_3\end{array}\right\}}}\underset{X\text{'}, m_{X\text{'}}=45,3 \left(g\right)}{\stackrel{quy đổi}{\to }\underbrace{\left\{\begin{array}{l}{K}^{+}: 0,45\\ C{a}^{2+}: x\\ O{H}^{-}: y\\ O^{2-}: 0,24\end{array}\right\}}}+\underset{0,24}{\underbrace{C{O}_2}}\end{array} \\ \begin{array}{l}\Rightarrow \left\{\begin{array}{l}{m}_{X\text{'}}=0,45.39+40x+17y+0,24.16=45,3\\ BT~NT: 0,45+2x=y+0,24.2\end{array}\right.\Rightarrow \left\{\begin{array}{l}x=0,33\\ y=0,63\end{array}\right.\\ \Rightarrow n_{CaC{l}_2}=n_{Ca}\Rightarrow m_{CaC{l}_2}=36,63 gam\end{array} \end{gathered}$$