Câu 1 : 

\(n_{Mg}=\dfrac{8.4}{24}=0.35\left(mol\right)\)

\(Mg+2HCl\rightarrow MgCl_2+H_2\)

\(0.35.......0.7.........0.35..........0.35\)

\(C\%_{HCl}=\dfrac{0.7\cdot36.5}{146}\cdot100\%=17.5\%\)

\(m_{\text{dung dịch sau phản ứng}}=8.4+146-0.35\cdot2=153.7\left(g\right)\)

\(C\%_{MgCl_2}=\dfrac{0.35\cdot95}{153.7}\cdot100\%=21.6\%\)

Câu 2 :

\(n_{CaCO_3}=\dfrac{10}{100}=0.1\left(mol\right)\)

\(n_{HCl}=\dfrac{114.1\cdot8\%}{36.5}=0.25\left(mol\right)\)

\(CaCO_3+2HCl\rightarrow CaCl_2+CO_2+H_2O\)

\(1................2\)

\(0.1.............0.25\)

\(LTL:\dfrac{0.1}{1}< \dfrac{0.25}{2}\Rightarrow HCldư\)

\(m_{\text{dung dịch sau phản ứng}}=10+114.1-0.1\cdot44=119.7\left(g\right)\)

\(C\%_{HCl\left(dư\right)}=\dfrac{\left(0.25-0.2\right)\cdot36.5}{119.7}\cdot100\%=1.52\%\)

\(C\%_{CaCl_2}=\dfrac{0.2\cdot111}{119.7}\cdot100\%=18.54\%\)

Câu 3 : 

\(n_{H_2}=\dfrac{6.72}{22.4}=0.3\left(mol\right)\)

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

\(0.3.......0.6......................0.3\)

\(m_{Fe}=0.3\cdot56=16.8\left(g\right)\)

\(m_{dd_{HCl}}=150\cdot1.2=180\left(g\right)\)

\(C\%_{HCl}=\dfrac{0.6\cdot36.5}{180}\cdot100\%=12.16\%\)

\(C_{M_{HCl}}=\dfrac{0.6}{0.15}=4\left(M\right)\)

`a)PTHH:`

`Fe + 2HCl -> FeCl_2 + H_2`

`0,15`  `0,3`             `0,15`     `0,15`       `(mol)`

`n_[Fe]=[8,4]/56=0,15(mol)`

`b)V_[H_2]=0,15.22,4=3,36(l)`

`c)V_[dd HCl]=[0,3]/[0,5]=0,6(l)`

`=>C_[M_[FeCl_2]]=[0,15]/[0,6]=0,25(M)`

\(a,n_{Fe}=\dfrac{8,4}{56}=0,15\left(mol\right)\)

PTHH: Fe + 2HCl ---> FeCl₂ + H₂

           0,15-->0,3----->0,15--->0,15

b, V_H2 = 0,15.22,4 = 3,36 (l)

\(c,V_{dd}=\dfrac{0,3}{0,5}=0,6\left(l\right)\\ \rightarrow C_{M\left(FeCl_2\right)}=\dfrac{0,15}{0,6}=0,25M\)

\(CaCO_3+ HCl → CaCl_2+H_2O +CO_2\)

\(n_{CaCO_3}=\dfrac{10}{40+12+16.3}=0,1(mol)\)

\(n_{HCl}=\dfrac{146}{1+35,5}=4(mol)\)

\(\Rightarrow n_{HCl_{dư}}=4-0,1=3,9(mol) ; n_{CaCl_2}=0,1(mol)\\\Rightarrow m_{\text{chất tan}} = m_{HCl_{dư}}+m_{CaCl_2}\\=0,39.(35,5+1)+0,1(40+35,5.2)=25,335(g)\)

Vậy...

PT: \(CaCO_3+2HCl→CaCl_2+H_2O+CO_2\)

\(n_{HCl_{dư}} = 4-0,1.2=3,8(mol) \Rightarrow m_{HCl_{dư}}=138,7 (g) \\ n_{CaCl_2}=0,1(mol) \Rightarrow m_{CaCl_2}=11,1(g) \\ m_{\text{chất tan}}=149,8 (g) \\ \Rightarrow C\%=\dfrac{149,8}{146+10} .100\%=96\%\).

\(n_{CO_2}=\dfrac{V}{22,4}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ n_{NaOH}=\dfrac{m}{M}=\dfrac{m_{dd}.C\%}{M}=\dfrac{200.16\%}{40}=0,8\left(mol\right)\)

Có: \(\dfrac{n_{NaOH}}{n_{CO_2}}=4\)

=> Phản ứng tạo muối Na₂CO₃

PT:

\(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)

0,2.       0,4            0,2

=> dd sau phản ứng có những chất tan là:

\(\left\{{}\begin{matrix}Na_2CO_3:0,2\left(mol\right)\\NaOH:0,4\left(mol\right)\end{matrix}\right.\)

m_dd spu=0,2.44+200=208,8(g)

\(\%m_{NaOH}=\dfrac{0,4.40}{208,8}.100\%=7,66\%\\\%m_{Na_2CO_3}=\dfrac{0,2.106}{208,8}.100\%=10,15\% \)

Câu 1:

nAl= 0,1(mol)

PTHH: 2Al + 6 HCl -> 2 AlCl3 + 3 H2 

nAlCl3= nAl=0,1(mol)

-> mAlCl3= 133,5 x 0,1= 13,35(g)

mddAlCl3= mAl + mddHCl - mH2 = 2,7 + 200 - 3/2 x 0,1 x 2= 202,4(g)

C%ddAlCl3= (13,35/202,4).100= 6,596%

bạn ơi, có nồng độ của dd HCl không? vì nếu làm ntn thì câu 1 đề bài không chặt chẽ

Mình đã giúp bạn ở dưới rồi nhé :)

PTHH: \(CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2\uparrow\)

a) Ta có: \(n_{CaCO_3}=\dfrac{2,5}{100}=0,025\left(mol\right)\)

\(\Rightarrow n_{HCl}=0,05mol\) \(\Rightarrow m_{ddHCl}=\dfrac{0,05\cdot36,5}{18\%}\approx10,14\left(g\right)\)

b) Theo PTHH: \(n_{CaCl_2}=n_{CO_2}=n_{CaCO_3}=0,025\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}m_{CaCl_2}=0,025\cdot111=2,775\left(g\right)\\m_{CO_2}=0,025\cdot44=1,1\left(g\right)\end{matrix}\right.\)

Mặt khác: \(m_{dd\left(saup/ứ\right)}=m_{Zn}+m_{ddHCl}-m_{CO_2}=11,54\left(g\right)\)

\(\Rightarrow C\%_{CaCl_2}=\dfrac{2,775}{11,54}\cdot100\%\approx24,05\%\)

CaCO₃+2HCl→CaCl₂+CO₂↑ +H₂O

\(+n_{CaCO_3}=\dfrac{2,5}{100}=0,025\left(mol\right)\)

\(+n_{HCl}=2n_{CaCO_3}=0,05\left(mol\right)\)

\(+m_{HCl}=0,05.98=4,9\left(gam\right)\)

\(+m_{dungdịchHCl}=\dfrac{4,9}{18}.100\%=27,2\left(gam\right)\)

\(+n_{CaCl}=n_{CaCO_3}=0,025\left(mol\right)\)

\(+m_{CaCl_2}=0,025.111=2,775\left(gam\right)\)

Theo ĐLBTKL ta có:

\(m_{CaCl_2}=2,5+27,2-0,025.44-0,025.18=28,15\left(gam\right)\)

C%=\(\dfrac{2,775}{28,15}.100\%\approx9,85\%\)

PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)

a) Ta có: \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\) \(\Rightarrow n_{HCl}=0,2mol\)

\(\Rightarrow m_{ddHCl}=\dfrac{0,2\cdot36,5}{10,95\%}\approx66,67\left(g\right)\)

b) Theo PTHH: \(n_{ZnCl_2}=n_{H_2}=n_{Zn}=0,1mol\)

\(\Rightarrow\left\{{}\begin{matrix}m_{ZnCl_2}=0,1\cdot136=13,6\left(g\right)\\m_{H_2}=0,1\cdot2=0,2\left(g\right)\end{matrix}\right.\)

Mặt khác: \(m_{dd}=m_{Zn}+m_{ddHCl}-m_{H_2}=72,97\left(g\right)\)

\(\Rightarrow C\%_{ZnCl_2}=\dfrac{13,6}{72,97}\cdot100\%\approx18,64\%\)

1.

n_Al=\(\dfrac{5,4}{27}\)=0,2 mol

m_HCl=\(\dfrac{175.14,6}{100}\)=25,55g

n_HCl=\(\dfrac{25,55}{36,5}\)=0,7

                     2Al + 6HCl → 2AlCl₃ + 3H₂↑

n trước pứ    0,2     0,7  

n pứ              0,2 →0,6  →    0,2  →  0,3  mol

n sau pứ       hết   dư 0,1

Sau pứ HCl dư.

m_HCl (dư)= 36,5.0,1=3,65g

m_{các chất sau pư}= 5,4 +175 - 0,3.2= 179,8g

m_AlCl3= 133,5.0,2=26,7g

C%_ddHCl (dư)= \(\dfrac{3,65.100}{179,8}=2,03%\)%

C%_ddAlCl3 = \(\dfrac{26,7.100}{179,8}\)= 14,85%

2.

           200ml= 0,2l

m_Mg= \(\dfrac{4,2}{24}=0,175mol\)

    Mg + 2HCl → MgCl₂ + H₂↑

0,175→ 0,35 → 0,175→0,175 mol

a) V_H2= 0,175.22,4=3,92l.

b)C%_dHCl= \(\dfrac{0,35}{0,2}=1,75\)M

\(n_{CaO}=\dfrac{14}{56}=0,25\left(mol\right)\)

\(m_{ct}=\dfrac{10,95.200}{100}=21,9\left(g\right)\)

\(n_{HCl}=\dfrac{21,9}{36,5}=0,6\left(mol\right)\)

Pt : \(CaO+2HCl\rightarrow CaCl_2+H_2O|\)

          1           2             1            1

         0,25     0,3          0,15

a) Lập tỉ số so sánh : \(\dfrac{0,25}{1}>\dfrac{0,3}{2}\)

                  ⇒ CaO dư , HCl phản ứng hết

                 ⇒ Tính toán dựa vào số mol của HCl

\(n_{CaCl2}=\dfrac{0,3.1}{2}=0,15\left(mol\right)\)

⇒ \(m_{CaCl2}=0,15.111=16,65\left(g\right)\)

b) \(m_{ddspu}=14+200=214\left(g\right)\)

\(C_{CaCl2}=\dfrac{16,65.100}{214}=7,78\)⁰/₀

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