PTHH: \(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\uparrow\)
\(4P+5O_2\underrightarrow{t^o}2P_2O_5\)
Ta có: \(\left\{{}\begin{matrix}n_{O_2}=\dfrac{1}{2}\cdot\dfrac{31,6}{158}\cdot50\%=0,05\left(mol\right)\\n_P=\dfrac{24,8}{31}=0,8\left(mol\right)\end{matrix}\right.\)
Xét tỉ lệ: \(\dfrac{0,8}{4}>\dfrac{0,05}{5}\) \(\Rightarrow\) Photpho còn dư, Oxi p/ứ hết
\(\Rightarrow n_{P_2O_5}=0,02\left(mol\right)\) \(\Rightarrow m_{P_2O_5}=0,02\cdot142=2,84\left(g\right)\)
PT: \(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)
Ta có: \(n_{KMnO_4}=\dfrac{31,6}{158}=0,2\left(mol\right)\)
Theo PT: \(n_{O_2\left(LT\right)}=\dfrac{1}{2}n_{KMnO_4}=0,1\left(mol\right)\)
Mà: H% = 50%
\(\Rightarrow n_{O_2\left(TT\right)}=0,1.50\%=0,05\left(mol\right)\)
Ta có: \(n_P=\dfrac{24,8}{31}=0,8\left(mol\right)\)
PT: \(4P+5O_2\underrightarrow{t^o}2P_2O_5\)
Xét tỉ lệ: \(\dfrac{0,8}{4}>\dfrac{0,05}{5}\), ta được P dư.
Theo PT: \(n_{P_2O_5}=\dfrac{2}{5}n_{O_2}=0,02\left(mol\right)\)
\(\Rightarrow m_{P_2O_5}=0,02.142=2,84\left(g\right)\)
Bạn tham khảo nhé!
\(KMnO_4--t^o->K_2MnO_4+MnO_2+O_2\)
158 32
31,6 \(x\)
Với \(H=50\%\) \(\Rightarrow x=\dfrac{31,6.32}{158}.50\%=3,2\left(g\right)\)
\(4P+5O_2--t^o->2P_2O_5\)
124 160
\(y\) 3,2
\(\Rightarrow y=\dfrac{124.3,2}{160}=2,48\left(g\right)\)