a) 2KClO3 \(\underrightarrow{to}\) 2KCl + 3O2
b) \(m_{O_2}=62,25-51,65=10,6\left(g\right)\)
\(\Rightarrow n_{O_2}=\dfrac{10,6}{32}=0,33125\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,33125\times22,4=7,42\left(l\right)\)
The PT: \(n_{KCl}=\dfrac{2}{3}n_{O_2}=\dfrac{2}{3}\times0,33125=\dfrac{53}{240}\left(mol\right)\)
\(\Rightarrow m_{KCl}=\dfrac{53}{240}\times74,5=16,452\left(g\right)\)