Câu 4:
\(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\\ a.Fe+H_2SO_4\rightarrow FeSO_4+H_2\\ 0,2.......0,2.........0,2.......0,2\left(mol\right)\\ b.a=C\%_{ddH_2SO_4}=\dfrac{0,2.98}{500}.100=3,92\%\\ c.V_{H_2\left(đktc\right)}=0,2.22,4=4,48\left(l\right)\)
Câu 5:
\(n_{Na_2CO_3}=\dfrac{10,6}{106}=0,1\left(mol\right)\\ m_{H_2O}=1,05.200=210\left(g\right)\\ m_{ddNa_2CO_3\left(sau\right)}=10,6+210=220,6\left(g\right)\\ C\%_{ddNa_2CO_3\left(sau\right)}=\dfrac{10,6}{220,6}.100\approx4,805\%\\ V_{ddNa_2CO_3}=200\left(ml\right)=0,2\left(l\right)\\ C_{MddNa_2CO_3}=\dfrac{0,1}{0,2}=0,5\left(M\right)\)
Câu 3:
\(n_{Zn}=\dfrac{0,65}{65}=0,01\left(mol\right)\\ a.Zn+2HCl\rightarrow ZnCl_2+H_2\\ 0,01........0,02........0,01.......0,01\left(mol\right)\\ b.m_{ZnCl_2}=136.0,01=1,36\left(g\right)\\ c.C_{MddHCl}=\dfrac{0,02}{0,05}=0,4\left(M\right)\\ d.V_{H_2\left(đktc\right)}=0,01.22,4=0,224\left(l\right)\)
Câu 2:
\(a.2H_2+O_2\underrightarrow{^{to}}2H_2O\\ b.4P+5O_2\underrightarrow{^{to}}2P_2O_5\\ c.2Na+2H_2O\rightarrow2NaOH+H_2\\ d.P_2O_5+3H_2O\rightarrow2H_3PO_4\)
Câu 1:
\(a.Đặt:Na^I_aO^{II}_b\left(a,b:nguyên,dương\right)\\ \Rightarrow I.a=II.b\\ \Leftrightarrow\dfrac{a}{b}=\dfrac{II}{I}=\dfrac{2}{1}\\ \Rightarrow\left\{{}\begin{matrix}a=2\\b=1\end{matrix}\right.\\ \Rightarrow CTHH:Na_2O\\ b.Đặt:C^{IV}_xS^{II}_y\left(x,y:nguyên,dương\right)\\ \Rightarrow x.IV=II.y\\ \Leftrightarrow\dfrac{x}{y}=\dfrac{II}{IV}=\dfrac{2}{4}=\dfrac{1}{2}\\\Rightarrow\left\{{}\begin{matrix}x=1\\y=2\end{matrix}\right.\\ \Rightarrow CTHH:CS_2\\ c.Đặt:Ba^{II}_x\left(SO_4\right)^{II}_y\left(x,y:nguyên,dương\right)\\ \Rightarrow x.II=y.II\\ \Leftrightarrow\dfrac{x}{y}=\dfrac{II}{II}=\dfrac{2}{2}=\dfrac{1}{1}\\ \Rightarrow\left\{{}\begin{matrix}x=1\\y=1\end{matrix}\right.\\ \Rightarrow CTHH:BaSO_4\)
