\(n_{KMnO_4}=\frac{632}{158}=4(mol)\\ a/ 2KMnO_4 \buildrel{{t^o}}\over\longrightarrow MnO_2+O_2+K_2MnO_4\\ b/\\ n_{MnO_2}=\frac{1}{2}.n_{KMnO_4}=\frac{1}{2}.4=2(mol)\\ m_{MnO_2}=87.2=174(g)\\ c// n_{O_2}=\frac{1}{2}.n_{KMnO_4}=\frac{1}{2}.4=2(mol)\\ V_{O_2}=2.22,4=44,8(l) \)
PTHH: \(2KMnO_4\xrightarrow[]{t^o}K_2MnO_4+MnO_2+O_2\)
Ta có: \(n_{O_2}=n_{MnO_2}=\dfrac{1}{2}n_{KMnO_4}=\dfrac{1}{2}\cdot\dfrac{632}{158}=2\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}m_{MnO_2}=2\cdot87=174\left(g\right)\\V_{O_2}=2\cdot22,4=44,8\left(l\right)\end{matrix}\right.\)