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\(n_{Zn}=\dfrac{26}{65}=0,4\left(mol\right)\)
PTHH :
\(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
0,4 0,8 0,4 0,4
\(a,m_{HCl}=0,8.36,5=29,2\left(g\right)\)
\(b,V_{H_2}=n.22,4=0,4.24,79=9,916\left(l\right)\)
\(c,m_{ZnCl_2}=0,4.136=21,76\left(g\right)\)
`Zn+2HCl->ZnCl_2+H_2↑`
`a,n_(Zn)=26/65=0,4(mol)`
`=>n_(HCl)=2n_(Zn)=2.0,4=0,8(mol)`
`=>m_(HCl)=0,8.36,5=29,2(g)`
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`b,` Từ câu `a,` suy ra `n_(H_2)=0,4(mol)`
`=>V_(H_2(đkc))=n_(H_2).24,79=0,4.24,79=9,913(l)`
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`c,` Từ câu `a,` ta suy ra `n_(ZnCl_2)=0,4(mol)`
`=>m_(ZnCl_2)=0,4.136=21,76(g)`
Bài 1 : Sửa ZnSO thành ZnSO4
\(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
Pt : \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)
Theo Pt : \(n_{Zn}=n_{H2SO4}=n_{ZnSO4}=n_{H2}=0,2\left(mol\right)\)
a) \(m_{H2SO4}=0,2.98=19,6\left(g\right)\)
b) \(m_{ZnSO4}=0,2.161=32,2\left(g\right)\)
c) \(V_{H2\left(dkc\right)}=0,2.24,79=4,958\left(l\right)\)
Bài 3 :
\(n_{O2}=\dfrac{9,6}{32}=0,3\left(mol\right)\)
\(2KClO_3\xrightarrow[]{t^o}2KCl+3O_2\)
0,2<-----------0,2<----0,3
a) \(m_{KClO3}=0,2.122,5=24,5\left(g\right)\)
b) Cách 1 : \(m_{KCl}=0,2.74,5=14,9\left(g\right)\)
cách 2 : \(BTKl:m_{KClO3}=m_{KCl}+m_{O2}\)
\(\Rightarrow m_{KCl}=m_{KClO3}-m_{O2}=24,5-9,6=14,9\left(g\right)\)
\(m_{H_2SO_4}=\dfrac{200\cdot9,8\%}{100\%}=19,6\left(g\right)\\ n_{H_2SO_4}=\dfrac{19,6}{98}=0,2\left(mol\right)\\ PTHH:2KOH+H_2SO_4\rightarrow K_2SO_4+2H_2O\\ \Rightarrow n_{KOH}=2n_{H_2SO_4}=0,4\left(mol\right)\\ \Rightarrow m_{KOH}=0,4\cdot\left(39+16+1\right)=22,4\left(g\right)\)
\(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\\a, 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\\ n_{H_2}=n_{H_2SO_4}=\dfrac{3}{2}.0,2=0,3\left(mol\right)\\ b,V_{H_2\left(đktc\right)}=0,3.22,4=6,72\left(l\right)\\ c,n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{2}.0,2=0,1\left(mol\right)\\ m_{Al_2\left(SO_4\right)_3}=0,1.342=34,2\left(g\right)\\ d,C\%_{ddH_2SO_4}=\dfrac{0,3.98}{200}.100\%=14,7\%\\ e,m_{ddmuoi}=5,4+200-0,3.2=204,8\left(g\right)\\ C\%_{ddAl_2\left(SO_4\right)_3}=\dfrac{34,2}{204,8}.100\%\approx16,699\%\)
\(a)2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\\ b)n_{Al}=\dfrac{5,4}{27}=0,2mol\\ 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
\(0,2-\rightarrow0,3--\rightarrow0,1--\rightarrow0,3\)
\(m_{H_2}=0,3.2=0,6g\\ c)m_{Al_2\left(SO_4\right)_3}=0,1.342=34,2g\\ d)C_{\%H_2SO_4}=\dfrac{0,3.98}{200}\cdot100=14,7\%\\ e)C_{\%Al_2\left(SO_4\right)_3}=\dfrac{34,2}{5,4+200-0,6}\cdot100=16,7\%\)
a, Kẽm + Hydrochloric acid \(\rightarrow\) Kẽm Chloride + khí Hydrogen
b. Theo ĐLBTKL, ta có:
\(m_{Zn}+m_{HCl}=m_{ZnCl_2}+m_{H_2}\\ \Rightarrow m_{ZnCl_2}=6,5+7,3-0,2=13,6g\)
d, PTHH: Zn + 2HCl\(\rightarrow\) ZnCl2 + H2
a, \(MgO+H_2SO_4\rightarrow MgSO_4+H_2O\)
b, Ta có: \(m_{H_2SO_4}=200.9,8\%=19,6\left(g\right)\)
\(\Rightarrow n_{H_2SO_4}=\dfrac{19,6}{98}=0,2\left(mol\right)\)
Theo PT: \(n_{MgO}=n_{MgSO_4}=n_{H_2SO_4}=0,2\left(mol\right)\)
\(\Rightarrow m_{MgO}=0,2.40=8\left(g\right)\)
c, Ta có: m dd sau pư = 8 + 200 = 208 (g)
\(\Rightarrow C\%_{MgSO_4}=\dfrac{0,2.120}{208}.100\%\approx11,54\%\)
Gọi x,y lần lượt là số mol của MgO, Fe3O4
Pt: MgO + H2SO4 --> MgSO4 + H2O
.......x............x..................x
......Fe3O4 + 4H2SO4 --> Fe2(SO4)3 + FeSO4 + 4H2O
.........y................4y..................y................y
Ta có hệ pt: \(\left\{{}\begin{matrix}40x+232y=35,84\\120x+552y=90,24\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0,2\\y=0,12\end{matrix}\right.\)
mMgO = 0,2 . 40 = 8 (g)
mFe3O4 = 35,84 - 8 = 27,84 (g)
nH2SO4 = x + 4y = 0,2 + 4 . 0,12 = 0,68 mol
mdd H2SO4 = \(\dfrac{0,68\times98}{9,8}.100=680\left(g\right)\)
mdd sau pứ = mhh + mdd H2SO4 = 35,84 + 680 = 715,84 (g)
C% dd MgSO4 = \(\dfrac{0,2.120}{715,84}.100\%=3,35\%\)
C% dd FeSO4 = \(\dfrac{0,12.152}{715,84}.100\%=2,548\%\)
C% dd Fe2(SO4)3 = \(\dfrac{0,12.400}{715,84}.100\%=6,705\%\)
`n_(H_2)=V/(22,4)=(3,36)/(22,4)=0,15(mol)`
\(PTHH:2Al+3H_2SO_4->Al_2\left(SO_4\right)_3+3H_2\)
tỉ lệ 2 ; 3 ; 1 ; 3
n(mol) 0,1<-------------------------------------0,15
`m_(Al)=n*M=0,1*27=2,7(g)`
`=>B`
Số mol H2SO4= 9,8 : 98 = 0,1 (mol)
PTHH: Zn + H2SO4 -> ZnSO4 + H2
0,1 mol 0,1 mol
mZnSO4= 0,1 x 161 = 16,1 (g)
=>Chọn D