2KMnO4 \(\underrightarrow{to}\) K2MnO4 + MnO2 + O2
\(n_{O_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
Theo PT: \(n_{KMnO_4}=2n_{O_2}=2\times0,1=0,2\left(mol\right)\)
\(\Rightarrow m_{KMnO_4}=0,2\times158=31,6\left(g\right)\)
\(n_{O_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
PTHH: \(2KMnO_4-t^o->K_2MnO_4+MnO_2+O_2\uparrow\)
Theo PT ta có: \(n_{KMnO_4}=\dfrac{0,1.2}{1}=0,2\left(mol\right)\)
=> \(m_{KMnO_4}=0,2.158=31,6\left(g\right)\)