a.b.\(n_{Mg}=\dfrac{4,8}{24}=0,2mol\)
\(n_{HCl}=\dfrac{18,25}{36,5}=0,5mol\)
\(Mg+2HCl\rightarrow MgCl_2+H_2\)
0,2 < 0,5 ( mol )
0,2 0,4 0,2 0,2 ( mol )
\(m_{HCl\left(dư\right)}=\left(0,5-0,4\right).36,5=3,65g\)
\(V_{H_2}=0,2.22,4=4,48l\)
c.Cách 1:
\(m_{MgCl_2}=0,2.95=19g\)
Cách 2:
\(m_{H_2}=0,2.2=0,4g\)
\(m_{HCl}=0,4.36,5=14,6g\)
Áp dụng ĐL BTKL, ta có:
\(m_{Mg}+m_{HCl}=m_{MgCl_2}+m_{H_2}\)
\(\Rightarrow m_{MgCl_2}=4,8+14,6-0,4=19g\)
a, \(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ n_{HCl}=\dfrac{18,25}{36,5}=0,5\left(mol\right)\)
PTHH: Mg + 2HCl ---> MgCl2 + H2
LTL: \(0,2< \dfrac{0,5}{2}\)=> HCl dư
\(\left\{{}\begin{matrix}n_{H_2}=n_{MgCl_2}=0,2\left(mol\right)\\n_{HCl\left(pư\right)}=0,2.2=0,4\left(mol\right)\end{matrix}\right.\\ \Rightarrow m_{dư}=\left(0,5-0,4\right).36,5=3,65\left(g\right)\)
b, VH2 = 0,2.22,4 = 4,48 (l)
c, C1: \(m_{MgCl_2}=0,2.95=19\left(g\right)\)
C2: Bảo toàn khối lượng:
\(m_{MgCl_2}=4,8+0,4.36,5-0,2.2=19\left(g\right)\)
