Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) \(n_{Al}=\dfrac{7,5.36\%}{27}=0,1\left(mol\right)\)
\(n_{Mg}=\dfrac{7,5-0,1.27}{24}=0,2\left(mol\right)\)
PTHH: 2Al + 6HCl --> 2AlCl3 + 3H2
0,1------------>0,1----->0,15
Mg + 2HCl --> MgCl2 + H2
0,2------------>0,2----->0,2
=> mmuối = 0,1.133,5 + 0,2.95 = 32,35 (g)
b) VH2 = (0,15 + 0,2).22,4 = 7,84 (l)
1. \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
2. \(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
Theo PT: \(n_{ZnCl_2}=n_{H_2}=n_{Zn}=0,2\left(mol\right)\Rightarrow m_{ZnCl_2}=0,2.136=27,2\left(g\right)\)
3. Ta có: \(n_{Fe_3O_4}=\dfrac{23,2}{232}=0,1\left(mol\right)\)
PT: \(Fe_3O_4+4H_2\underrightarrow{^{t^o}}3Fe+4H_2O\)
Xét tỉ lệ: \(\dfrac{0,1}{1}>\dfrac{0,2}{4}\), ta được Fe3O4 dư.
Theo PT: \(n_{Fe_3O_4\left(pư\right)}=\dfrac{1}{4}n_{H_2}=0,05\left(mol\right)\Rightarrow n_{Fe_3O_4\left(dư\right)}=0,1-0,05=0,05\left(mol\right)\)
\(\Rightarrow m_{Fe_3O_4\left(dư\right)}=0,05.232=11,6\left(g\right)\)
1. \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
2. \(n_{zn}=\dfrac{m_{Zn}}{M_{Zn}}=\dfrac{13}{65}=0,2\left(mol\right)\)
Theo PTHH: \(n_{ZnCl_2}=n_{Zn}=0,2\left(mol\right)\)
\(\Rightarrow m_{ZnCl_2}=n_{ZnCl_2}.M_{ZnCl_2}=0,2.136=27,2\left(g\right)\)
\(\Rightarrow n_{H_2}=n_{Zn}=0,2\left(mol\right)\)
3. \(2H_2+Fe_3O_4\rightarrow3Fe+2H_2O\)
2 mol------1 mol------3 mol--2 mol
\(n_{Fe_3O_4}=\dfrac{m_{Fe_3O_4}}{M_{Fe_3O_4}}=\dfrac{23,2}{232}=0,1\left(mol\right)\)
\(\dfrac{n_{Fe_3O_4}}{1}=\dfrac{0,1}{1}\)
\(\dfrac{n_{H_2}}{2}=\dfrac{0,2}{2}\)
\(\dfrac{n_{Fe_3O_4}}{1}=\dfrac{n_{H_2}}{2}\)
Vậy không có chất nào dư cả
a) \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)
PTHH: 2Al + 6HCl --> 2AlCl3 + 3H2
0,2---------------------->0,3
=> VH2 = 0,3.22,4 = 6,72 (l)
b)
\(n_{CuO}=\dfrac{32}{80}=0,4\left(mol\right)\)
PTHH: CuO + H2 --to--> Cu + H2O
Xét tỉ lệ: \(\dfrac{0,4}{1}>\dfrac{0,3}{1}\) => CuO dư, H2 hết
PTHH: CuO + H2 --to--> Cu + H2O
0,3<--0,3------->0,3
=> Rắn sau pư gồm \(\left\{{}\begin{matrix}Cu:0,3\left(mol\right)\\CuO\left(dư\right):0,1\left(mol\right)\end{matrix}\right.\)
\(\left\{{}\begin{matrix}\%m_{Cu}=\dfrac{0,3.64}{0,3.64+0,1.80}.100\%=70,59\%\\\%m_{CuO}=\dfrac{0,1.80}{0,3.64+0,1.80}.100\%=29,41\%\end{matrix}\right.\)
Câu 1:
\(n_S=\dfrac{m_S}{M_S}=\dfrac{3,2}{32}=0,1\left(mol\right)\)
PTHH: H2 + S -t0> H2S
Tỉ lệ: 1 1 1
Mol: 0,1 0,1 0,1
\(m_{H_2S}=n_{H_2S}.M_{H_2S}=0,1
.
34=3,4\left(g\right)\)
Câu 2:
\(n_{CuO}=\dfrac{m_{CuO}}{M_{CuO}}=\dfrac{8}{80}=0,1\left(mol\right)\)
PTHH: CuO + H2 -t0> Cu + H2O
Tỉ lệ: 1 1 1 1
Mol: 0,1 0,1 0,1 0,1
Tính khối lượng của cái nào bạn?
Ví dụ là Cu:
\(m_{Cu}=n_{Cu}
.
M_{Cu}=0,1
.
64=6,4\left(g\right)\)
Ví dụ là H2O:
\(m_{H_2O}=n_{H_2O}
.
M_{H_2O}=0,1
.
18=1,8\left(g\right)\)
\(n_{Zn}=\dfrac{m}{M}=\dfrac{32,5}{65}=0,5\left(mol\right)\\ PTHH:Zn+2HCl->ZnCl_2+H_2\)
tỉ lệ 1 : 2 : 1 : 1
n(mol) 0,5------------------------------->0,5
\(V_{H_2\left(dktc\right)}=n\cdot22,4=0,5\cdot22,4=11,2\left(l\right)\)
a) \(n_{Mg}=\dfrac{6}{24}=0,25\left(mol\right)\)
PTHH: Mg + H2SO4 --> MgSO4 + H2
0,25----------------------->0,25
=> VH2 = 0,25.22,4 = 5,6 (l)
b)
\(n_{Fe_2O_3}=\dfrac{32}{160}=0,2\left(mol\right)\)
PTHH: Fe2O3 + 3H2 --to--> 2Fe + 3H2O
Xét tỉ lệ: \(\dfrac{0,2}{1}>\dfrac{0,25}{3}\) => H2 hết
PTHH: Fe2O3 + 3H2 --to--> 2Fe + 3H2O
0,25----->\(\dfrac{1}{6}\)
=> \(m_{Fe}=\dfrac{1}{6}.56=\dfrac{28}{3}\left(g\right)\)
a) \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
0,1-------------->0,1------>0,1
\(\Rightarrow m_{ZnCl_2}=0,1.136=13,6\left(g\right)\)
b) \(V_{H_2}=0,1.22,4=2,24\left(l\right)\)
c) \(CuO+H_2\xrightarrow[]{t^o}Cu+H_2O\)
0,1<---0,1
\(\Rightarrow m_{CuO}=0,1.80=8\left(g\right)\)
a: Zn+2HCl->ZnCl2+H2
0,2 0,4 0,2 0,2
mZnCl2=0,2*136=27,2(g)
b: V=0,2*22,4=4,48(lít)
a, \(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\)
PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
Theo PT: \(n_{H_2}=n_{Zn}=0,3\left(mol\right)\Rightarrow V_{H_2}=0,3.22,4=6,72\left(l\right)\)
b, \(n_{CuO}=\dfrac{30}{80}=0,375\left(mol\right)\)
PT: \(CuO+H_2\underrightarrow{t^o}Cu+H_2O\)
Xét tỉ lệ: \(\dfrac{0,375}{1}>\dfrac{0,3}{1}\), ta được CuO dư.
Theo PT: \(n_{Cu}=n_{H_2}=0,3\left(mol\right)\Rightarrow m_{Cu}=0,3.64=19,2\left(g\right)\)
phần xét tỉ lệ là sao v ạ