\(n_P=\dfrac{12,4}{31}=0,4\left(mol\right);n_{O_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ 4P+5O_2\rightarrow\left(t^o\right)2P_2O_5\\ Vì:\dfrac{0,4}{4}>\dfrac{0,2}{5}\Rightarrow P.dư\\ n_{P\left(dư\right)}=0,4-\dfrac{5}{4}.0,2=0,15\left(mol\right)\\ m_{P\left(Dư\right)}=0,15.31=4,65\left(g\right)\)
PTHH: \(4P+5O_2\xrightarrow[]{t^o}2P_2O_5\)
\(n_P=\dfrac{12,4}{31}=0,4\left(mol\right)\)
\(n_{O_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
Ta có: \(\dfrac{n_P}{4}=\dfrac{0,4}{4}\)
\(\dfrac{n_{O_2}}{5}=\dfrac{0,2}{5}\)
\(\Rightarrow\dfrac{n_P}{4}>\dfrac{n_{O_2}}{5}\)
Vậy phốt pho dư
\(n_{P\text{Pứ}}=\dfrac{0,4.4}{5}=0,32\left(mol\right)\)
\(n_{Pdư}=n_P-n_{PPứ}=0,4-0,32=0,08\left(mol\right)\)
Khối lượng phốt pho dư:
\(m_{Pdư}=n_{Pdư}.M_P=0,08.31=2,48g\)
