a) \(Zn + H_2SO_4 \rightarrow ZnSO_4 + H_2\)

Cu không pư H₂SO₄ loãng

b)

\(n_{H_2}=\dfrac{2,24}{22,4}= 0,1 mol\)

Theo PTHH:

\(n_{Zn}= n_{H_2}= 0,1 mol\)

\(\Rightarrow m_{Zn}= 0,1 . 65= 6,5 g\)

\(\Rightarrow m_{Cu}= m_{hh KL} - m_{Zn}= 10 - 6,5 = 3,5 g\)

Gọi \(n_{Cu}=x\left(mol\right)\)\(;n_{Zn}=y\left(mol\right)\)

\(n_{H_2}=\dfrac{2,24}{22,4}=0,1mol\)

\(Zn+2HCl\rightarrow ZnCl_2+H_2\)

0,1                                   0,1

\(m_{Zn}=0,1\cdot65=6,5g\)

\(m_{Cu}=10-6,4=3,6g\)

a)    Cu không tác dụng với H₂SO₄ loãng

        Zn + H₂SO₄→ZnSO₄ + H₂

b) n_H2=2,24/22,4= 0,1 mol

⇒mAl= 0,1. 27=2,7 gam

⇒ mCu= 10-mAl = 10-2,7 =7,3 gam

nH2=0,1(mol)

PTHH: Mg + 2 HCl -> MgCl2 + H2

0,1__________0,2___________0,1(mol)

MgO + 2 HCl -> MgCl2 + H2O

0,05____0,1___0,05(mol)

mMg=0,1. 24= 2,4(g) -> mMgO=4,4-2,4= 2(g) -> nMgO=0,05((mol)

b) %mMg= (2,4/4,4).100=54,545%

=> %mMgO=45,455%

c) nHCl=0,3(mol) -> mHCl=0,3.36,5=10,95(g)

=> mddHCl=(10,95.100)/7,3=150(g)

a)Mg+2CH3COOH→Mg(CH3COO)2+H2

Zn+2CH3COOH→Zn(CH3COO)2+H2

nH2=0,3mol

Gọi a và b lần lượt là số mol của Mg và Zn

\(\left\{{}\begin{matrix}24a+65b=11,3\\a+b=0,3\end{matrix}\right.\)

→a=0,2,b=0,1

→mMg=0,2×24=4,8g

→mZn=0,1×65=6,5g

b)%mMg=\(\dfrac{4,8}{11,3}\)×100%=42,48%

%mZn=\(\dfrac{6,5}{11,3}\)×100%=57,52%

c)nCH3COOH=2nMg+2nZn=0,6mol

→mCH3COOH=0,6×60=36g

→C%CH3COOH=\(\dfrac{36}{200}\)×100%=18%

→nMg(CH3COO)2=nMg=0,2mol

→nZn(CH3COO)2=nZn=0,1mol

→mMg(CH3COO)2=0,2×142=28,4g

→mZn(CH3COO)2=0,1×183=18,3g

nH2=nMg+nZn=0,3mol

→mH2=0,6g

→mddmuối=mhỗnhợp+mddCH3COOH−mH2

→mddmuối=11,3+200−0,6=210,7g

→C%Mg(CH3COO)2=\(\dfrac{28,4}{210,7}\)×100%=13,48%

→C%Zn(CH3COO)2=\(\dfrac{18,3}{210,7}\)×100%=8,69%

PTHH: \(2Mg+O_2\underrightarrow{t^o}2MgO\)  (1)

            \(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)  (2)

a) Gọi số mol của Mg là a (mol) \(\Rightarrow n_{Al}=\dfrac{2}{3}a\left(mol\right)\)

\(\Rightarrow24a+27\cdot\dfrac{2}{3}a=6,3\) \(\Rightarrow a=0,15\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{MgO}=0,15\left(mol\right)\\n_{Al_2O_3}=0,05\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{MgO}=0,15\cdot40=6\left(g\right)\\m_{Al_2O_3}=0,05\cdot102=5,1\left(g\right)\end{matrix}\right.\)

b) Theo các PTHH: \(\left\{{}\begin{matrix}n_{O_2\left(1\right)}=0,075\left(mol\right)\\n_{O_2\left(2\right)}=0,075\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow\Sigma n_{O_2}=0,15\left(mol\right)\) \(\Rightarrow V_{O_2}=0,15\cdot22,4=3,36\left(l\right)\)

a, \(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

PTHH: Zn + 2HCl → ZnCl₂ + H₂

Mol:     0,2                              0,2

(do Cu ko tác dụng với HCl loãng)

b, \(m_{Zn}=0,2.65=13\left(g\right)\)

  \(m_{Cu}=19,4-13=6,4\left(g\right)\)

ta có :

2Mg+O2-to>2MgO

x--------0,5x

2Zn+O2-to>2ZnO

y-------0,5y

=>\(\left\{{}\begin{matrix}24x+65y=14,58\\0,5x+0,5y=0,15\end{matrix}\right.\)

=>x=0,12 mol ,y=0,18 mol

=>%mMg=\(\dfrac{0,12.24}{14,58}100\)=19,753%

=>%mZn=80,247%

\(n_{O_2}=\dfrac{4,8}{32}=0,15mol\)

Gọi \(\left\{{}\begin{matrix}n_{Mg}=x\\n_{Zn}=y\end{matrix}\right.\)

\(2Mg+O_2\rightarrow\left(t^o\right)2MgO\)

  x        1/2 x                       ( mol )

\(2Zn+O_2\rightarrow\left(t^o\right)2ZnO\)

  y       1/2 y                         ( mol )

Ta có:

\(\left\{{}\begin{matrix}24x+65y=14,58\\\dfrac{1}{2}x+\dfrac{1}{2}y=0,15\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}x=0,12\\y=0,18\end{matrix}\right.\)

\(\rightarrow\left\{{}\begin{matrix}m_{Mg}=0,12.24=2,88g\\m_{Zn}=0,18.65=11,7g\end{matrix}\right.\)

\(\rightarrow\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{2,88}{14,58}.100=19,75\%\\\%m_{Zn}=100\%-19,75\%=80,25\%\end{matrix}\right.\)

\(n_{O_2}=\dfrac{4,8}{32}=0,15\left(mol\right)\) 
gọi số mol Mg : a , số mol Zn : b (a,b>0) 
pthh : \(2Mg+O_2\underrightarrow{t^o}2MgO\) 
         a          \(\dfrac{1}{2}a\) 
         \(2Zn+O_2\underrightarrow{t^o}2ZnO\) 
         b         \(\dfrac{1}{2}b\) 
mà 24a + 65b=14,58  
có : \(\dfrac{1}{2}a+\dfrac{1}{2}b=0,15\) 
=> a = 0,12 ( mol ) , b=0,18 (mol) 
=> \(\%m_{Zn}=\dfrac{0,18.65}{14,68}.100\%=79,7\%\\ \%m_{Mg}=100\%-79,7\%=20,3\%\)