a, PT: \(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)
Ta có: \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)
Theo PT: \(n_{O_2}=\dfrac{3}{4}n_{Al}=0,15\left(mol\right)\Rightarrow V_{O_2}=0,15.22,4=3,36\left(l\right)\)
b, PT: \(CH_4+2O_2\underrightarrow{t^o}CO_2+2H_2O\)
Ta có: \(n_{CH_4}=\dfrac{6.10^{22}}{6.10^{23}}=0,1\left(mol\right)\)
Theo PT: \(n_{O_2}=2n_{CH_4}=0,2\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,2.22,4=4,48\left(l\right)\)
c, Ta có: \(n_S=\dfrac{3,2}{32}=0,1\left(mol\right)\)
\(n_P=\dfrac{6,2}{31}=0,2\left(mol\right)\)
PT: \(S+O_2\underrightarrow{t^o}SO_2\)
\(4P+5O_2\underrightarrow{t^o}2P_2O_5\)
Theo PT: \(n_{O_2}=n_S+\dfrac{5}{4}n_P=0,35\left(mol\right)\)
\(\Rightarrow V_{O_2}=0,35.22,4=7,84\left(l\right)\)