a) \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)

PTHH: Zn + 2HCl --> ZnCl₂ + H₂

           0,1-->0,2------>0,1-->0,1

=> V_H2 = 0,1.22,4 = 2,24 (l)

m_ZnCl2 = 0,1.136 = 13,6 (g)

b) \(C\%_{dd.HCl}=\dfrac{0,2.36,5}{200}.100\%=3,65\%\)

c) \(n_{O_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)

PTHH: 2H₂ + O₂ --t^o--> 2H₂O

Xét tỉ lệ: \(\dfrac{0,1}{2}< \dfrac{0,15}{1}\) => H₂ hết, O₂ dư

PTHH: 2H₂ + O₂ --t^o--> 2H₂O

            0,1--------------->0,1

=> m_H2O = 0,1.18 = 1,8 (g)

\(n_{HCl}=\dfrac{50.18,25}{100.36,5}=0,25(mol)\\ K_2CO_3+2HCl\to 2KCl+H_2O+CO_2\uparrow\\ a,n_{CO_2}=0,125(mol)\\ \Rightarrow V_{CO_2}=0,125.22,4=2,8(l)\\ b,n_{K_2CO_3}=0,125(mol)\\ \Rightarrow m_{K_2CO_3}=0,125.138=17,25(g)\\ c,n_{KCl}=0,25(mol)\\ \Rightarrow C\%_{KCl}=\dfrac{0,25.74,5}{17,25+50-0,125.44}.100\%=30,16\%\)

a) K₂CO₃ + 2HCl --> 2KCl + CO₂ + H₂O

b) \(n_{K_2CO_3}=\dfrac{13,8}{138}=0,1\left(mol\right)\)

PTHH: K₂CO₃ + 2HCl --> 2KCl + CO₂ + H₂O

______0,1----->0,2------>0,2--->0,1

=> V_CO2 = 0,1.22,4 = 2,24 (l)

c) m_HCl = 0,2.36,5 = 7,3 (g)

\(m_{ddHCl}=\dfrac{7,3.100}{7,3}=100\left(g\right)\)

d) m_KCl = 0,2.74,5 = 14,9 (g)

m_{dd sau pư} = 13,8 + 100 - 0,1.44 = 109,4 (g)

=> \(C\%\left(KCl\right)=\dfrac{14,9}{109,4}.100\%=13,62\%\)

\(a)n_{Fe}=\dfrac{5,6}{56}=0,1mol\\ n_{HCl}=0,5.1=0,5mol\\ Fe+2HCl\rightarrow FeCl_2+H_2\\ \Rightarrow\dfrac{0,1}{1}< \dfrac{0,5}{2}\Rightarrow HCl.dư\\ Fe+2HCl\rightarrow FeCl_2+H_2\)
0,1         0,2          0,1          0,1

\(m_{HCl\left(dư\right)}=\left(0,5-0,2\right).36,5=10,95g\\ b)m_{FeCl_2}=0,1.127=12,7g\\ c)V_{H_2}=0,1.22,4=2,24l\\ d)C_{\%HCl\left(dư\right)}=\dfrac{10,95}{200}\cdot100=5,475\%\\ C_{\%HCl\left(pư\right)}=\dfrac{0,2.36,5}{200}\cdot100=3,65\%\)

n Zn= 19,5/65=0,3 (mol).

PTPƯ: Zn(0.3) +   HCl(0.6) ---->  ZnCl2(0.3) + H2(0,3)

mHCl=0,6.36.5=21.9(g)

a) C%HCl= 21.9/300.100%=7,3%

b) VH2=0,3.22,4=6,72(lít)

c) mH2=0,3.2=0,6(g)

mZnCl2=0,3.136=40,8(g)

mddZnCl2 =(19,5+300)-0,6=318,9(g)

C%=mZnCl2/mddZnCl2.100= 40,8/318,9.100=12,793%

PTHH: \(K_2CO_3+2HCl\rightarrow2KCl+H_2O+CO_2\uparrow\)

Ta có: \(n_{CO_2}=\dfrac{0,224}{22,4}=0,01\left(mol\right)\)

\(\Rightarrow n_{HCl}=0,02\left(mol\right)=n_{KCl}\) \(\Rightarrow\left\{{}\begin{matrix}C_{M_{HCl}}=\dfrac{0,02}{0,01}=2\left(M\right)\\m_{KCl}=0,02\cdot74,5=1,49\left(g\right)\end{matrix}\right.\)

a) PTHH: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)

b) Ta có: \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\) \(\Rightarrow n_{HCl}=0,3\left(mol\right)\)

\(\Rightarrow C\%_{HCl}=\dfrac{0,3\cdot36,5}{100}\cdot100\%=10,95\%\)

c+d) Theo PTHH: \(\left\{{}\begin{matrix}n_{H_2}=0,3\left(mol\right)\\n_{AlCl_3}=0,2\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{H_2}=0,3\cdot22,4=6,72\left(l\right)\\m_{H_2}=0,3\cdot2=0,6\left(g\right)\\m_{AlCl_3}=0,2\cdot133,5=26,7\left(g\right)\end{matrix}\right.\)

Mặt khác: \(m_{dd}=m_{Al}+m_{ddHCl}-m_{H_2}=104,8\left(g\right)\)

\(\Rightarrow C\%_{AlCl_3}=\dfrac{26,7}{104,8}\cdot100\%\approx25,48\%\)

`a)PTHH:`

`Zn + 2HCl -> ZnCl_2 + H_2`

`0,2`   `0,4`                `0,2`      `0,2`       `(mol)`

`n_[Zn]=13/65=0,2(mol)`

`b)V_[H_2]=0,2.22,4=4,48(l)`

`c)m_[dd HCl]=[0,4.36,5]/5 . 100=292(g)`

`=>C%_[ZnCl_2]=[0,2.136]/[13+292-0,2.2].100~~8,93%`

Zn + 2HCl → ZnCl₂ + H₂

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

n Zn=0,2 mol

=>VH2=0,2.22,4=4,48l

=>mddHcl=292g

C%=\(\dfrac{0,2.136}{13+292-0,2.2}100=8,929\%\)

a. Zn (0,2 mol) + 2HCl (0,4 mol) \(\rightarrow\) ZnCl₂ (0,2 mol) + H₂ (0,2 mol).

b. Số mol Zn là 13:65=0,2 (mol).

Thể tích khí H₂ thu được ở đktc là 0,2.22,4=4,48 (l).

c. Khối lượng dung dịch là 0,4.36,5.100:5+13-0,2.2=304,6 (g).

Nồng độ phần trăm cần tìm là 0,2.136/304,6.100%\(\approx\)8,93%.

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

PTHH: Fe + 2HCl --> FeCl₂ + H₂

          0,1-->0,2------>0,1--->0,1

=> \(m_{FeCl_2}=0,1.127=12,7\left(g\right)\)

b) m_{dd sau pư} = 5,6 + 200 - 0,1.2 = 205,4 (g)

=> \(C\%=\dfrac{12,7}{205,4}.100\%=6,18\%\)