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a)\(n_{Fe_2O_3}=0,2\left(mol\right)\)

PT:\(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)

     \(0,2\)          \(1,2\)          \(0,4\)

\(\Rightarrow n_{FeCl_3}=0,4\left(mol\right)\)

\(\Rightarrow m_{FeCl_3}=65\left(g\right)\)

b) \(n_{HCl}=\dfrac{218.30\%}{35,5+1}=\dfrac{654}{365}\left(mol\right)\)

Từ PT \(\Rightarrow\)\(n_{HClpư}=1,2\left(mol\right)\)

\(\Rightarrow n_{HCldư}=\dfrac{654}{365}-1,2=\dfrac{216}{365}\left(mol\right)\)

\(\Rightarrow m_{HCldư}=21,6\left(g\right)\)

\(m_{dd}=32+218=250\left(g\right)\)

\(C\%_{FeCl_3}=\dfrac{65}{250}.100\%=26\left(\%\right)\)

\(C\%_{HCldu}=\dfrac{21,6}{250}.100\%=8,64\%\)

a, \(Fe+2HCl\rightarrow FeCl_2+H_2\)

\(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

Theo PT: \(n_{Fe}=n_{FeCl_2}=n_{H_2}=0,3\left(mol\right)\Rightarrow m_{Fe}=0,3.56=16,8\left(g\right)\)

b, \(n_{HCl}=2n_{H_2}=0,6\left(mol\right)\Rightarrow C_{M_{HCl}}=\dfrac{0,6}{0,15}=4\left(M\right)\)

c, \(FeCl_2+2NaOH\rightarrow2NaCl+Fe\left(OH\right)_2\)

Theo PT: \(n_{NaOH}=2n_{FeCl_2}=0,6\left(mol\right)\)

\(\Rightarrow V_{NaOH}=\dfrac{0,6}{1}=0,6\left(l\right)=600\left(ml\right)\)

\(a.Fe+2HCl\rightarrow FeCl_2+H_2\\ n_{Fe,pư}=n_{FeCl_2}=n_{H_2}=\dfrac{6,72}{22,4}=0,3mol\\ m_{Fe,pư}=0,3.56=16,8g\\ b.n_{HCl}=0,3.2=0,6mol\\ C_{M_{HCl}}=\dfrac{0,6}{0,15}=4M\\ c.2NaOH+FeCl_2\rightarrow Fe\left(OH\right)_2+2NaCl\\ n_{NaOH}=0,3.2=0,6mol\\ V_{ddNaOH}=\dfrac{0,6}{1}=0,6l=600ml\)

a) PTHH: \(BaCO_3+2HCl\rightarrow BaCl_2+H_2O+CO_2\uparrow\)

Ta có: \(\left\{{}\begin{matrix}n_{BaCO_3}=\dfrac{68,95}{197}=0,35\left(mol\right)\\n_{HCl}=0,25\cdot3,2=0,8\left(mol\right)\end{matrix}\right.\)

Xét tỉ lệ: \(\dfrac{0,35}{1}< \dfrac{0,8}{2}\) \(\Rightarrow\) Axit còn dư 

\(\Rightarrow n_{HCl\left(dư\right)}=0,8-0,35\cdot2=0,1\left(mol\right)\) \(\Rightarrow m_{HCl\left(dư\right)}=0,1\cdot36,5=3,65\left(g\right)\)

b+c) Theo PTHH: \(\left\{{}\begin{matrix}n_{CO_2}=n_{BaCl_2}=0,35\left(mol\right)\\n_{HCl\left(dư\right)}=0,1\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{CO_2}=0,35\cdot22,4=7,84\left(l\right)\\C_{M_{BaCl_2}}=\dfrac{0,35}{0,25}=1,4\left(M\right)\\C_{M_{HCl\left(dư\right)}}=\dfrac{0,1}{0,25}=0,4\left(M\right)\end{matrix}\right.\) 

\(n_{FeO}=\dfrac{14,4}{72}=0,2\left(mol\right)\)

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

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

Pt : \(FeO+2HCl\rightarrow FeCl_2+H_2O|\)

         1           2             1            1

        0,2       0,6            0,2

a) Lập tỉ số so sánh : \(\dfrac{0,2}{1}< \dfrac{0,6}{2}\)

             ⇒ FeO phản ứng hết , HCl dư

             ⇒ Tính toán dựa vào số mol của FeO

\(n_{HCl\left(dư\right)}=0,6-\left(0,2.2\right)=0,2\left(mol\right)\)

⇒ \(m_{HCl\left(dư\right)}=0,2.36,5=7,3\left(g\right)\)

b) \(n_{FeCl2}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)

⇒ \(m_{FeCl2}=0,2.127=25,4\left(g\right)\)

\(m_{ddspu}=14,4+200=214,4\left(g\right)\)

\(C_{FeCl2}=\dfrac{25,4.100}{214,4}=11,85\)⁰/₀

\(C_{HCl\left(dư\right)}=\dfrac{7,3.100}{214,4}=3,4\)⁰/₀

 Chúc bạn học tốt

a,\(n_{FeO}=\dfrac{14,4}{72}=0,2\left(mol\right)\)

 \(m_{HCl}=10,95\%.200=21,9\left(g\right)\Rightarrow n_{HCl}=\dfrac{21,9}{36,5}=0,6\left(mol\right)\)

PTHH: FeO + 2HCl → FeCl₂ + H₂O

Mol:      0,2      0,4         0,2

Ta có: \(\dfrac{0,2}{1}< \dfrac{0,6}{2}\) ⇒ FeO pứ hết ,HCl dư

m_{HCl dư} = (0,6-0,4).36,5 = 7,3 (g)

b, \(m_{FeCl_2}=0,2.127=25,4\left(g\right)\)

c, m_{dd sau pứ} = 14,4+200 = 214,4 (g)

\(C\%_{ddFeCl_2}=\dfrac{25,4.100\%}{214,4}=11,847\%\)

\(C\%_{ddHCldư}=\dfrac{7,3.100\%}{214,4}=3,4\%\)

Học tốt nheee

\(n_{MgO}=\dfrac{8}{40}=0,2\left(mol\right)\)

a) Pt : \(MgO+2HCl\rightarrow MgCl_2+H_2O|\)

             1             2             1              1

           0,2          0,4          0,2

b) \(n_{MgCl2}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)

⇒ \(m_{MgCl2}=0,2.95=19\left(g\right)\)

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

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

\(m_{ddHCl}=\dfrac{14,6.100}{10}=146\left(g\right)\)

d) \(m_{ddspu}=8+146=154\left(g\right)\)

\(C_{MgCl2}=\dfrac{19.100}{154}=12,34\)⁰/₀

 Chúc bạn học tốt