Câu 15 : 

\(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\)

Pt : \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

     0,4----->1,2------->0,4------>0,6

\(m_{HCl}=1,2.36,5=43,8\left(g\right)\)

\(\Rightarrow m_{ddHCl}=\dfrac{43.8.100\%}{25\%}=175,2\left(g\right)\)

\(m_{ddspu}=10,8+175,2-0,6.2=184,8\left(g\right)\)

\(C\%_{AlCl3}=\dfrac{0,4.133,5}{184,8}.100\%=28,9\%\)

em cảm ơn ạ

a)

\(PTHH:Fe+2HCl\rightarrow FeCl_2+H_2\)

b)

\(n_{Fe}=\dfrac{5,6}{56}=0,1mol\)

Theo PT:\(n_{HCl}=2n_{Fe}=0,2mol\)

\(\Rightarrow C_MHCl=\dfrac{0,2}{0,2}=1M\)

c)

Theo PT:\(n_{H_2}=n_{Fe}=0,1mol\)

\(\Rightarrow V_{H_2}=0,1.22,4=2,24l\) 

\(a)Zn+2HCl\rightarrow ZnCl_2+H_2\\ b)n_{Zn}=\dfrac{13}{65}=0,2mol\\ n_{Zn}=n_{ZnCl_2}=n_{H_2}=0,2mol\\ V_{H_2}=0,2.22,4=4,48l\\ c)n_{HCl}=0,2.2=0,4mol\\ C_{M_{HCl}}=\dfrac{0,4}{0,2}=2M\\ d)m_{ZnCl_2}=0,2.136=27,2g\)

a) Viết phương trình hóa học

\(Z n + 2 H C l \rightarrow Z n C l_{2} + H_{2} \uparrow\)

b) Tính thể tích khí sinh ra (ở đktc)

Số mol kẽm:

\(n_{Z n} = \frac{13}{65} = 0 , 2 \&\text{nbsp};\text{mol}\)

Theo phương trình:

\(n_{H_{2}} = n_{Z n} = 0 , 2 \&\text{nbsp};\text{mol}\)

Thể tích khí hiđro ở đktc:

\(V_{H_{2}} = 0 , 2 \times 22 , 4 = 4 , 48 \&\text{nbsp}; \text{l} \overset{ˊ}{\imath} \text{t}\)

Đáp số: \(V_{H_{2}} = 4 , 48\) lít.

c) Tính nồng độ mol/l của dung dịch HCl đã dùng

Theo phương trình:

\(n_{H C l} = 2 n_{Z n} = 2 \times 0 , 2 = 0 , 4 \&\text{nbsp};\text{mol}\)

Thể tích dung dịch HCl:

\(V = 200 \&\text{nbsp};\text{ml} = 0 , 2 \&\text{nbsp}; \text{l} \overset{ˊ}{\imath} \text{t}\)

Nồng độ mol:

\(C_{M} = \frac{n}{V} = \frac{0 , 4}{0 , 2} = 2 \&\text{nbsp};\text{mol}/\text{l}\)

Đáp số: \(C_{M} \left(\right. H C l \left.\right) = 2 M\).

d) Tính khối lượng muối sinh ra

Theo phương trình:

\(n_{Z n C l_{2}} = n_{Z n} = 0 , 2 \&\text{nbsp};\text{mol}\)

Khối lượng mol của \(Z n C l_{2}\):

\(M_{Z n C l_{2}} = 65 + 35 , 5 \times 2 = 136 \&\text{nbsp};\text{g}/\text{mol}\)

Khối lượng muối:

\(m_{Z n C l_{2}} = 0 , 2 \times 136 = 27 , 2 \&\text{nbsp};\text{g}\)

Đáp số: \(m_{Z n C l_{2}} = 27 , 2\) gam.

a. PTHH: Zn + H₂SO₄ ---> ZnSO₄ + H₂↑

b. Ta có: \(C_{M_{H_2SO_4}}=\dfrac{n_{H_2SO_4}}{200:1000}=1,5M\)

=> \(n_{H_2SO_4}=0,3\left(mol\right)\)

Ta lại có: \(n_{Zn}=\dfrac{16,25}{65}=0,25\left(mol\right)\)

Ta thấy: \(\dfrac{0,3}{1}>\dfrac{0,25}{1}\)

Vậy H₂SO₄ dư.

Theo PT: \(n_{H_2}=n_{Zn}=0,25\left(mol\right)\)

=> \(V_{H_2}=0,25.22,4=5,6\left(lít\right)\)

c. Theo PT: \(n_{ZnSO_4}=n_{Zn}=0,25\left(mol\right)\)

=> \(m_{ZnSO_4}=0,25.161=40,25\left(g\right)\)

d. Ta có: \(V_{dd_{ZnSO_4}}=0,2\left(lít\right)\)

=> \(C_{M_{ZnSO_4}}=\dfrac{0,25}{0,2}=1,25M\)

\(n_{Al}=\dfrac{10,8}{27}=0,4(mol)\\ a,2Al+3H_2SO_4\to Al_2(SO_4)_3+3H_2\\ \Rightarrow n_{H_2}=n_{H_2SO_4}=0,6(mol);n_{Al_2(SO_4)_3}=0,2(mol)\\ b,V_{H_2}=0,6.22,4=13,44(l)\\ c,m_{dd_{H_2SO_4}}=\dfrac{0,6.98}{9,8\%}=600(g)\\ \Rightarrow C\%_{Al_2(SO_4)_3}=\dfrac{0,2.342}{10,8+600-0,6.2}.100\%=11,22\%\)

Dạ cám ơn .

Bài 4 : 

\(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)

a) Pt : \(Zn+2HCl\rightarrow ZnCl_2+H_2|\)

            1          2              1          1

          0,2        0,4           0,2        0,2

b) \(n_{H2}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)

\(V_{H2\left(dktc\right)}=0,2.22,4=4,48\left(l\right)\)

c) \(n_{HCl}=\dfrac{0,2.2}{1}=0,4\left(mol\right)\)

⇒ \(m_{HCl}=0,4.36,5=14,6\left(g\right)\)

\(C_{ddHCl}=\dfrac{14,6.100}{100}=14,6\)⁰/₀

d) \(n_{ZnCl2}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)

⇒ \(m_{ZnCl2}=0,2.136=27,2\left(g\right)\)

\(m_{ddspu}=13+100-\left(0,2.2\right)=112,6\left(g\right)\)

\(C_{ZnCl2}=\dfrac{27,2.100}{112,6}=24,16\)⁰/₀

 Chúc bạn học tốt

Bài 3 : 

\(n_{Mg}=\dfrac{12}{24}=0,5\left(mol\right)\)

a) Pt : \(Mg+H_2SO_4\rightarrow MgSO_4+H_2|\)

            1            1                1           1

          0,5          0,5            0,5          0,5

b) \(n_{H2}=\dfrac{0,5.1}{1}=0,5\left(mol\right)\)

\(V_{H2\left(dktc\right)}=0,5.22,4=11,2\left(l\right)\)

c) \(n_{H2SO4}=\dfrac{0,5.1}{1}=0,5\left(mol\right)\)

⇒ \(m_{H2SO4}=0,5.98=49\left(g\right)\)

\(C_{ddH2SO4}=\dfrac{49.100}{200}=24,5\)⁰/₀

d) \(n_{MgSO4}=\dfrac{0,5.1}{1}=0,5\left(mol\right)\)

⇒ \(m_{MgSO4}=0,5.120=60\left(g\right)\)

\(m_{ddspu}=12+200-\left(0,5.2\right)=211\left(g\right)\)

\(C_{MgSO4}=\dfrac{60.100}{211}=28,44\)⁰/₀

 Chúc bạn học tốt

\(n_{H_2}=\dfrac{7,84}{22,4}=0,35\left(mol\right)\)

PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)

____0,35_____0,7___________0,35 (mol)

a, \(m_{Zn}=0,35.65=22,75\left(g\right)\)

b, \(C\%_{HCl}=\dfrac{0,7.36,5}{200}.100\%=12,775\%\)

\(a)n_{H_2}=\dfrac{7,84}{22,4}=0,35mol\\ Zn+2HCl\rightarrow ZnCl_2+H_2\)

0,35        0,7            0,35         0,35

\(m_{Zn}=0,35.65=22,75g\\ b)C_{\%HCl}=\dfrac{0,7.36,5}{200}\cdot100\%=12,775\%\)

\(n_{ZnO}=\dfrac{16.2}{81}=0.2\left(mol\right)\)

\(ZnO+H_2SO_4\rightarrow ZnSO_4+H_2O\)

CM H2SO4 = 0.2/0.1 = 2 (M) 

mZnSO4 = 0.2*161 = 32.2 (g) 

\(a,PTHH:Na_2CO_3+2HCl\rightarrow2NaCl+H_2O+CO_2\uparrow\\ b,n_{Na_2CO_3}=\dfrac{15,9}{106}=0,15\left(mol\right)\\ \Rightarrow n_{HCl}=0,3\left(mol\right)\\ \Rightarrow m_{CT_{HCl}}=0,3\cdot36,5=10,95\left(g\right)\\ \Rightarrow C\%_{HCl}=\dfrac{10,95}{200}\cdot100\%=5,475\%\\ c,n_{CO_2}=0,15\left(mol\right)\\ \Rightarrow V_{CO_2\left(đkc\right)}=0,15\cdot24,79=3,7185\left(l\right)\\ d,m_{CO_2}=0,15\cdot44=6,6\left(g\right)\\ n_{NaCl}=0,3\left(mol\right);n_{H_2O}=0,15\left(mol\right)\\ \Rightarrow\left\{{}\begin{matrix}m_{CT_{NaCl}}=0,3\cdot58,5=17,55\left(g\right)\\m_{H_2O}=0,15\cdot18=2,7\left(g\right)\end{matrix}\right.\\ m_{dd_{NaCl}}=15,9+200-2,7-6,6=206,6\left(g\right)\\ \Rightarrow C\%_{NaCl}=\dfrac{17,55}{206,6}\cdot100\%\approx8,49\%\)