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nH2nH2=1,34422,41,34422,4=0,06 (mol)
Cu+HCl→Cu+HCl→ ko pứ
Fe+2HCl→FeCl2+H2↑Fe+2HCl→FeCl2+H2↑
0,06 0,12 ←0,06 (mol)
%mFe=0,06.56/13.100 % ≈25,85 %
%mCu=100 % - 25,85 %=74,15 %
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mctHCll=0,12.26,5=4,38 (g)
mddHCll=4,38.100/15 =29,2 (g)
Đặt \(\left\{{}\begin{matrix}n_{Zn}=x\left(mol\right)\\n_{Mg}=y\left(mol\right)\end{matrix}\right.\Rightarrow65x+24y=8,9\left(1\right)\)
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ PTHH:Zn+2HCl\rightarrow ZnCl_2+H_2\\ Mg+2HCl\rightarrow MgCl_2+H_2\\ \Rightarrow x+y=0,2\left(2\right)\\ \left(1\right)\left(2\right)\Rightarrow\left\{{}\begin{matrix}65x+24y=8,9\\x+y=0,2\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,1\left(mol\right)\\y=0,1\left(mol\right)\end{matrix}\right.\\ \Rightarrow\%_{Zn}=\dfrac{0,1\cdot65}{8,9}\cdot100\%\approx73\%\\ \Rightarrow\%_{Mg}=100\%-73\%=27\%\)
\(n_{HCl}=2x+2y=0,4\left(mol\right)\\ \Rightarrow m_{CT_{HCl}}=0,4\cdot36,5=14,6\left(g\right)\\ \Rightarrow m_{dd_{HCl}}=\dfrac{14,6\cdot100\%}{14,6\%}=100\left(g\right)\)
\(n_{H2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
a) Pt : \(Zn+2HCl\rightarrow ZnCl_2+H_2|\)
1 2 1 1
0,2 0,2
b) \(n_{Zn}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)
\(m_{Zn}=0,2.65=13\left(g\right)\)
\(m_{Cu}=19,4-13=6,4\left(g\right)\)
Chúc bạn học tốt
\(n_{H_2}=\dfrac{4,48}{22,4}=0,2mol\)
\(n_{HCl}=0,2mol\)
\(n_{H_2SO_4}=0,2mol\)
\(n_{H\left(axit\right)}=n_{HCl}+2n_{H_2SO_4}=0,2+0,2.2=0,6mol\)
\(\rightarrow\)\(n_{H\left(axit\right)}=0,6>2n_{H_2}=0,4\rightarrow\)axit dư
\(n_{Zn}=x;n_{Mg}=y\)
Ta có hệ: \(\left\{{}\begin{matrix}65x+24y=8,9\\x+y=0,2\end{matrix}\right.\)
Giải ra x=y=0,1
%Zn=\(\dfrac{65.0,1.100}{8,9}\approx73\%\)
%Mg=27%
\(n_{Fe}=x(mol);n_{Mg}=y(mol)\\ \Rightarrow 56x+24y=10-2=8(1)\\ Fe+2HCl\to FeCl_2+H_2\\ Mg+2HCl\to MgCl_2+H_2\\ \Rightarrow x+y=\dfrac{4,48}{22,4}=0,2(2)\\ (1)(2)\Rightarrow x=y=0,1(mol)\\ a,\begin{cases} \%_{Fe}=\dfrac{56.0,1}{10}.100\%=56\%\\ \%_{Mg}=\dfrac{24.0,1}{10}.100\%=24\%\\ \%_{Cu}=\dfrac{2}{10}.100\%=20\% \end{cases}\\ \)
\(b,\Sigma n_{HCl}=2(x+y)=0,4(mol)\\ \Rightarrow V=\dfrac{0,4}{2}=0,2(l)\)
Ta có: \(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
a. PTHH:
\(Mg+2HCl--->MgCl_2+H_2\uparrow\left(1\right)\)
\(Cu+HCl--\times-->\)
b. Theo PT(1): \(n_{Mg}=n_{H_2}=0,2\left(mol\right)\)
\(\Rightarrow m_{Mg}=0,2.24=4,8\left(g\right)\)
\(\Rightarrow\%_{m_{Mg}}=\dfrac{4,8}{11,2}.100\%=42,9\%\)
\(\%_{m_{Cu}}=100\%-42,9\%=57,1\%\)
c. Theo PT(1): \(n_{HCl}=2.n_{H_2}=2.0,2=0,4\left(mol\right)\)
PTHH: \(NaOH+HCl--->NaCl+H_2O\left(2\right)\)
Theo PT(2): \(n_{NaOH}=n_{HCl}=0,4\left(mol\right)\)
\(\Rightarrow m_{NaOH}=0,4.40=16\left(g\right)\)
\(n_{H_2}=\dfrac{2.24}{22.4}=0.1\left(mol\right)\)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
\(0.1.......0.2......................0.1\)
Chất rắn X : Cu
\(m_{Zn}=0.1\cdot65=6.5\left(g\right)\Rightarrow m_{Cu}=19.3-6.5=12.8\left(g\right)\)
\(n_{Cu}=\dfrac{12.8}{64}=0.2\left(mol\right)\)
\(C_{M_{HCl}}=\dfrac{0.2}{0.2}=1\left(M\right)\)
\(2Cu+O_2\underrightarrow{^{^{t^o}}}2CuO\)
\(0.2........0.1\)
\(m_{tăng}=m_{O_2}=0.1\cdot32=3.2\left(g\right)\)
Mg + HCl = MgCl2 + H2
a a
Fe + HCl = FeCl2 + H2
b b
Zn + HCl = ZnCl2 + H2
c c
Gọi a,b,c lần lượt là số mol Mg,Fe,Zn. Theo đề bài VH2 do sắt tạo ra gấp 2 lần thể tích H2 do Mg tạo ra. Do đó b = 2a
Số mol khí H2 là : nH2 = 17,92/22,4 = 0,8
Ta có : ⎧⎨⎩24a+56b+65ca+b+cb=2a{24�+56�+65��+�+��=2� ⇒⎧⎨⎩a=0,1(mol)b=0,2(mol)c=0,5(mol)⇒{�=0,1(���)�=0,2(���)�=0,5(���)
Thành phần % khối lượng mỗi kim loại là :
%Mg=0,1.24.10046,1=5,2%%��=0,1.24.10046,1=5,2%
%Fe=0,2.56.10046,1=24,3%%��=0,2.56.10046,1=24,3%
%Zn=0,5.65.10046,1=70,5%
a) Gọi \(\left\{{}\begin{matrix}n_{Zn}=a\left(mol\right)\\n_{Mg}=b\left(mol\right)\end{matrix}\right.\Rightarrow65a+24b=8,4\left(1\right)\)
Ta có: \(\left\{{}\begin{matrix}n_{HCl}=0,3.2=0,6\left(mol\right)\\n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\end{matrix}\right.\)
PTHH:
`Zn + 2HCl -> ZnCl_2 + H_2`
`Mg + 2HCl -> MgCl_2 + H_2`
Theo PT: `n_{HCl} = 2n_{H_2} = 0,4 (mol) < 0,6 (mol)`
`=> HCl` dư, hh kim loại tan hết
Theo PT: `n_{H_2} = n_{Mg} + n_{Zn}`
`=> a + b = 0,2(2)`
`(1), (2) =>` \(\left\{{}\begin{matrix}a=\dfrac{18}{205}\\b=\dfrac{23}{205}\end{matrix}\right.\)
`=>` \(\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{\dfrac{18}{205}.65}{8,4}.100\%=67,94\%\\\%m_{Mg}=100\%-67,94\%=32,06\%\end{matrix}\right.\)