\(n_P=0,25\left(mol\right);n_{O_2}=0,25\left(mol\right)\\ 4P+5O_2-^{t^o}\rightarrow2P_2O_5\\ LTL:\dfrac{0,25}{4}>\dfrac{0,25}{5}\Rightarrow Pdư\\ n_{P\left(dư\right)}=0,25-\dfrac{0,25.4}{5}=0,05\left(mol\right)\\n_{P_2O_5}=\dfrac{2}{5}n_{O_2}=0,1\left(mol\right)\\ m_{P_2O_5}=0,1.142=14,2\left(g\right) \)