\(n_{O_2}=\dfrac{3.36}{22.4}=0.15\left(mol\right)\)
\(2KMnO_4\underrightarrow{t^0}K_2MnO_4+MnO_2+O_2\)
\(0.3............................................0.15\)
\(m_{KMnO_4}=0.3\cdot158=47.4\left(g\right)\)
\(n_{O_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
\(2KMnO_4\xrightarrow[]{t^o}K_2MnO_4+MnO_2+O_2\)
\(0,3\) \(0,15\) \(\left(mol\right)\)
\(m_{KMnO_4}=0,3.158=47,4\left(g\right)\)