Câu hỏi 5

\(\begin{gathered}
\left\{ \begin{gathered}
Al:x \hfill \\
Na:y \hfill \\
BaO:z \hfill \\
\end{gathered} \right. + {H_2}O \to {H_2}:0,085 = 1,5x + 0,5y(1) \hfill \\
{\text{DD}}Y + \left\{ \begin{gathered}
0,03mol\,{H_2}S{O_4} \hfill \\
HCl:0,1 \hfill \\
\end{gathered} \right. \to 7,43(g)\,muoi + 3,11(g)ket\,tua \hfill \\
G/s\,S{O_4}^{2 - }\,het \to {m_{BaS{O_4}}} = 0,03.233 = 6,99(g) > m \downarrow (loai) \hfill \\
\to B{a^{2 + }}\,het \hfill \\
{n_{BaS{O_4}}} = z(mol) \hfill \\
{n_{Al{{(OH)}_3}}} = t(mol) \hfill \\
\to 233z + 78t = 3,11(2) \hfill \\
{m_{muoi}} = 7,43 = 0,03.96 + 0,1.35,5 + 27(x - t) + 23y(3) \hfill \\
{n_{{H^ + }}} = 0,16 = 2z + y + 3(x - t)(4) \hfill \\
\to \left\{ \begin{gathered}
x = 0,04 \hfill \\
y = 0,05 \hfill \\
z = 0,01 \hfill \\
t = 0,01 \hfill \\
\end{gathered} \right. \to m = 3,76(g) \hfill \\
\end{gathered} \)

Đáp án B