$d H_{2}/ hh=16\Rightarrow \overline{M}(khí)=32 $lập sơ đồ đường chéo đc $\frac{n_{CO}}{n_{CO_{2}}}=3$, lại có$ V_{hh}=0.896\Rightarrow n_{hh}=0.04$
$\Rightarrow n_{CO}=0.03,n_{CO_{2}}=0.01\Rightarrow n_{O_{2}}=\frac{2*0.01+0.03}{2}=0.025$
$2KCl_{3}\rightarrow 2KCl+3O_{2}$
$x(mol).............\frac{3}{2}x$
$2KMnO_{4}\rightarrow K_{2}MnO_{4}+MnO_{2}+O_{2}$
$y(mol)............................\frac{1}{2}y$
$\Rightarrow hpt\begin{cases}122.5x+158y= 4.385\\ \frac{3}{2}x+\frac{1}{2}y=0.025 \end{cases}\Leftrightarrow \begin{cases}x=0.01 \\ y= 0.02\end{cases}$
$\Rightarrow $ %m $KClO_{3}=27.94$%