Ta có: \(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)
\(n_{O_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
PT: \(2Mg+O_2\underrightarrow{t^o}2MgO\)
Xét tỉ lệ: \(\dfrac{0,2}{2}< \dfrac{0,2}{1}\), ta được O2 dư.
a, Theo PT: \(n_{O_2\left(pư\right)}=\dfrac{1}{2}n_{Mg}=0,1\left(mol\right)\)
\(\Rightarrow n_{O_2\left(dư\right)}=0,1\left(mol\right)\Rightarrow V_{O_2\left(dư\right)}=0,1.22,4=2,24\left(l\right)\)
b, Theo PT: \(n_{MgO}=n_{Mg}=0,2\left(mol\right)\)
\(\Rightarrow m_{MgO}=0,2.40=8\left(g\right)\)
Bạn tham khảo nhé!
a.
\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)
\(n_{O_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
PTHH : 2Mg + O2 -> 2MgO
0,2 0,1 0,2 ( mol )
Xét tỉ lệ : \(\dfrac{0,2}{2}< \dfrac{0,2}{1}\) => Mg đủ , O2 dư
\(n_{O_2\left(dư\right)}=0,2-0,1=0,1\left(mol\right)\)
\(m_{O_2\left(dư\right)}=0,1.32=3,2\left(g\right)\)
\(V_{O_2\left(dư\right)}=0,1.22,4=2,24\left(l\right)\)
b.
\(m_{MgO}=0,2.40=8\left(g\right)\)
\(a,n_{O_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ PTHH:2Mg+O_2\rightarrow\left(t^o\right)2MgO\\ Vì:\dfrac{0,2}{2}< \dfrac{0,2}{1}\Rightarrow Mghết,O_2dư\\ n_{O_2\left(p.ứ\right)}=\dfrac{1}{2}.n_{Mg}=\dfrac{0,2}{2}=0,1\left(mol\right)\\ \Rightarrow n_{O_2\left(dư\right)}=0,2-0,1=0,1\left(mol\right)\\ \Rightarrow V_{O_2\left(dư,đktc\right)}=0,1.22,4=2,24\left(l\right)\\ b,n_{MgO}=n_{Mg}=0,2\left(mol\right)\\ \Rightarrow m_{MgO}=0,2.40=8\left(g\right)\)