\(a)n_{O_2}=\dfrac{V}{24,79}=\dfrac{11,2}{24,79}\approx0,45\left(mol\right)\\ \Rightarrow m_{O_2}=n.M=0,45.\left(16.2\right)=14,4\left(g\right)\\ b)n_{NaCl}=\dfrac{V}{24,79}=\dfrac{12,5}{24,79}\approx0,505\left(mol\right)\\ \Rightarrow m_{NaCl}=n.M=0,505.\left(23+35,5\right)=29,5425\left(g\right).\)
\(n_{O_2}=\dfrac{11.2}{22.4}=0.5\left(mol\right)\\ m_{O_2}=n\cdot M=0.5\cdot32=16\left(gam\right)\)
\(n_{NaCl}=\dfrac{12.5}{22.4}\approx0.5\left(mol\right)\\ m_{NaCl}=n\cdot M=0.5\cdot\text{58.5}=29.25\left(gam\right)\)