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a, PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)
b, Ta có: \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
Theo PT: \(n_{Zn}=n_{H_2}=0,1\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,1.65}{20}.100\%=32,5\%\\\%m_{Al_2O_3}=67,5\%\end{matrix}\right.\)
c, Ta có: mAl2O3 = 20 - 0,1.65 = 13,5 (g)
\(\Rightarrow n_{Al_2O_3}=\dfrac{13,5}{102}=\dfrac{9}{68}\left(mol\right)\)
Theo PT: \(n_{HCl}=2n_{Zn}+6n_{Al_2O_3}=\dfrac{169}{170}\left(mol\right)\)
\(\Rightarrow V_{ddHCl}=\dfrac{\dfrac{169}{170}}{1}\approx0,994\left(l\right)\)
d, Theo PT: \(\left\{{}\begin{matrix}n_{ZnCl_2}=n_{Zn}=0,1\left(mol\right)\\n_{AlCl_3}=2n_{Al_2O_3}=\dfrac{9}{34}\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{ZnCl_2}=0,1.136=13,6\left(g\right)\\m_{AlCl_3}=\dfrac{9}{34}.133,5\approx35,34\left(g\right)\end{matrix}\right.\)
nH2SO4 = 1 . 0,3 = 0,3 mol
Pt: Fe + H2SO4 --> FeSO4 + H2
...0,3........0,3.............0,3.........0,3
mFe pứ = 0,3 . 56 = 16,8 (g)
VH2 thoát ra = 0,3 . 22,4 = 6,72 (lít)
CM FeSO4 = \(\dfrac{0,3}{0,3}=1M\)
\(n_{Zn}=\dfrac{26}{65}=0,4\left(mol\right)\\ pthh:Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
0,4 0,8 0,4 0,4
\(a,V_{H_2}=0,4.22,4=8,96\left(l\right)\\ b,C\%_{HCl}=\dfrac{0,8.36,5}{150}.100\%=19,5\%\\ c,m_{\text{dd}}=26+150-\left(0,4.2\right)=175,2\left(g\right)\\ C\%_{ZnCl_2}=\dfrac{0,4.136}{175,2}.100\%=31\%\)
a) \(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)
b) \(n_{Mg}=\dfrac{7,2}{24}=0,3\left(mol\right)\)
\(m_{dd}=m_{ct}+m_{dm}=7,2+150=157,2\left(g\right)\)
\(\Rightarrow C\%=\dfrac{7,2}{157,2}.100\%\approx4,6\%\)
c) Theo PTHH: \(n_{H_2}=n_{Mg}=0,3\left(mol\right)\)
\(\Rightarrow V_{H_2}=0,3.22,4=6,72\left(l\right)\)
`n_[Zn]=13/65=0,2(mol)`
`Zn + 2HCl -> ZnCl_2 + H_2 \uparrow`
`0,2` `0,4` `0,2` `(mol)`
`a)V_[H_2]=0,2.22,4=4,48(l)`
`b)C%_[HCl]=[0,4.36,5]/150 .100~~9,73%`
Zn + 2HCl => ZnCl2 + H2
nHCl = 0.2x2 = 0.4 (mol)
Theo pt => nZn = 0.2 (mol) = nH2
mZn = n.M = 0.2 x 65 = 13 (g)
VH2 = 22.4 x n = 22.4 x 0.2 = 4.48 (l)
nZnCl2 = 0.2 (mol); 200 ml = 0.2 (l)
CM dd sau pứ = 0.2/0.2 = 1M
Zn +2HCl --->ZnCl2 +H2
a) Ta có
n\(_{H2}=\frac{0,896}{22.4}0,04\left(mol\right)\)
Theo pthh\
n\(_{Zn}=n_{H2}=0,04\left(mol\right)\)
m\(_{Zn}=0.04.65=2,6\left(g\right)\)
n\(_{HCl}=2n_{H2}=0,08\left(mol\right)\)
m\(_{HCl}=0,08.36,5=2,92\left(g\right)\)
b)Theo pthh
n\(_{ZnCl2}=n_{H2}=0,04\left(mol\right)\)
m\(_{ZnCl2}=0,04.136=5,44\left(g\right)\)
m\(_{axit}=\frac{2,29.100}{14,6}15,68\left(g\right)\)
m\(_{dd}=2,6+15,68-0,08=18,2\left(g\right)\)
C%\(=\frac{5,44}{15,68}.100\%=29,89\%\)
Nhớ tích cho mình nhé
PTHH: \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\uparrow\)
Ta có: \(n_{H_2SO_4}=0,3\cdot1=0,3\left(mol\right)=n_{Zn}=n_{ZnSO_4}=n_{H_2}\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Zn}=0,3\cdot65=19,5\left(g\right)\\V_{H_2}=0,3\cdot22,4=6,72\left(l\right)\\C_{M_{ZnSO_4}}=\dfrac{0,3}{0,3}=1\left(M\right)\end{matrix}\right.\)