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\(n_{Na_2CO_3}=\dfrac{200.13,25%}{100\%.106}=0,25(mol)\\ n_{BaCl_2}=\dfrac{20,8\%.300}{100\%.208}=0,3(mol)\\ PTHH:Na_2CO_3+BaCl_2\to BaSO_4\downarrow +2NaCl\)
Vì \(\dfrac{n_{Na_2CO_3}}{1}<\dfrac{n_{BaCl_2}}{1}\) nên \(BaCl_2\) dư
Do đó dd sau p/ứ gồm \(BaCl_2\) dư và \(NaCl\)
\(n_{BaSO_4}=0,25(mol);n_{NaCl}=0,5(mol);n_{BaCl_2(dư)}=0,3-0,25=0,05(mol)\\ \Rightarrow m_{NaCl}=0,5.58,5=29,25(g);m_{BaCl_2(dư)}=0,05.208=10,4(g)\\ \Rightarrow C\%_{NaCl}=\dfrac{29,25}{200+300-0,25.233}.100\%=6,62\%\\ C\%_{BaCl_2(dư)}=\dfrac{10,4}{200+300-0,25.233}.100\%=2,35\%\)
a. \(nFe=\dfrac{11,2}{56}=0,2\left(mol\right)\)
\(mHCl=\dfrac{200.9,125}{100}=18,25\left(g\right)\)
\(nHCl=\dfrac{18,25}{36,5}=0,5\left(mol\right)\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
1 2 1 1 (mol)
0,2 0,4 0,2 0,2
LTL : \(\dfrac{0,2}{1}< \dfrac{0,5}{2}\)
=> Fe đủ , HCl dư
mHCl ( dư ) = 0,1 . 36,5 = 3,65(g)
b.
mFeCl2 = 0,2 . 127 = 25,4 (g)
mH2 = 0,2 . 2 = 0,4 (g)
mdd = mFe + mdd HCl + mFeCl2 - mH2
mdd = 11,2 + 200 + 25,4 - 0,4 = 236,2(g)
\(C\%_{ddHCl}=\dfrac{3,65.100}{236,2}=1,55\%\)
\(C\%_{FeCl_2}=\dfrac{25,4.100}{236,2}=10,75\%\)
\(C\%_{H_2}=\dfrac{0,4.100}{236,2}=0,17\%\)
\(\begin{cases} m_{H_2SO_4}=\dfrac{100.19,6\%}{100\%}=19,6(g)\\ m_{BaCl_2}=\dfrac{300.20,8\%}{100\%}=62,4(g) \end{cases} \Rightarrow \begin{cases} n_{H_2SO_4}=\dfrac{19,6}{98}=0,2(mol)\\ n_{BaCl_2}=\dfrac{62,4}{208}=0,3(mol) \end{cases}\\ a,PTHH:BaCl_2+H_2SO_4\to BaSO_4\downarrow +2HCl\)
Vì \(\dfrac{n_{H_2SO_4}}{1}<\dfrac{n_{BaCl_2}}{1}\) nên \(BaCl_2\) dư
\(\Rightarrow n_{BaSO_4}=0,2(mol)\\ \Rightarrow m_{BaSO_4}=0,2.233=46,6(g)\)
\(b,n_{HCl}=n_{BaSO_4}=0,2(mol)\\ \Rightarrow m_{CT_{HCl}}=0,2.36,5=7,3(g)\\ m_{dd_{HCl}}=100+300-46,6=353,4(g)\\ \Rightarrow C\%_{HCl}=\dfrac{7,3}{353,4}.100\%\approx 2,07\%\)
mNa2CO3=100*19.96/100=19.96g
nNa2CO3=19.96/106=0.19mol
mBaCl2=200*10.04/100=20.08g
nBaCl2=20.08/208=0.097mol
Na2CO3 + BaCl2 -> BaCO3 + 2NaCl
(mol) 1 1
(mol) 0.19 0.097
Lập tỉ lệ: 0.19> 0.097. Na2Co3 dư dư
Na2CO3 + BaCl2 -> BaCO3 + 2NaCl
(mol) 0.097 0.097 0.097 0.194
mdd = mddNa2CO3 + mddBaCl2 - mBaCO3
=100+200-0.097*197=208.891g
nNa2CO3 dư = 0.19-0.097=0.093mol
mNa2CO3 dư = 0.093*106=9.858g
mNaCl = 0.194*58.5=11.349g
C%Na2CO3 dư = 9.858/208.891*100=4.72%
C%NaCl = 11.349/208.891*100=5.43%
\(a)n_{Na_2CO_3}=\dfrac{10,6}{106}=0,1mol\\ n_{BaCl_2}=\dfrac{15,6}{208}=0,075mol\\ Na_2CO_3+BaCl_2\rightarrow BaCO_3+2NaCl\\ \Rightarrow\dfrac{0,1}{1}>\dfrac{0,075}{1}\Rightarrow Na_2CO_3.dư\\ n_{BaCO_3}=n_{Na_2CO_3,pứ}=n_{BaCl_2}=0,075mol\\ m_{BaCO_3}=0,075.197=14,775g\\ b)m_{Na_2CO_3,dư}=\left(0,1-0,075\right)106=2,65g\)
Bài 19 :
\(a) n_{Al} = \dfrac{10,8}{27} = 0,4(mol)\\ 2Al + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2\\ n_{H_2} = \dfrac{3}{2}n_{Al} = 0,6(mol)\\ V_{H_2} = 0,6.22,4 = 13,44(lít)\\ b) \text{Chất tan : }Al_2(SO_4)_3\\ n_{Al_2(SO_4)_3} = \dfrac{1}{2}n_{Al} = 0,2(mol)\\ m_{Al_2(SO_4)_3} = 0,2.342 = 68,4(gam)\)
Bài 18 :
\(a) n_{HCl} = \dfrac{250.7,3\%}{36,5 } = 0,5(mol)\\ Zn + 2HCl \to ZnCl_2 + H_2\\ n_{H_2} = \dfrac{1}{2}n_{HCl} = 0,25(mol) \Rightarrow V_{H_2} = 0,25.22,4 = 5,6(lít)\\ b) \text{Chất tan : } ZnCl_2\\ n_{ZnCl_2} = n_{H_2} = 0,25(mol)\\ m_{ZnCl_2} = 0,25.136 = 34(gam)\)
PTHH: \(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\uparrow\)
a) Ta có: \(\left\{{}\begin{matrix}n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\\n_{H_2SO_4}=\dfrac{200\cdot4,9\%}{98}=0,1\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\) Cả 2 chất p/ứ hết
b+c) Theo PTHH: \(n_{ZnSO_4}=n_{H_2}=n_{Zn}=0,1\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}m_{ZnSO_4}=0,1\cdot161=16,1\left(g\right)\\m_{H_2}=0,1\cdot2=0,2\left(g\right)\end{matrix}\right.\)
Mặt khác: \(m_{dd}=m_{Zn}+m_{ddH_2SO_4}-m_{H_2}=206,3\left(g\right)\)
\(\Rightarrow C\%_{ZnSO_4}=\dfrac{16,1}{206,3}\cdot100\%\approx7,8\%\)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
trc p/u : 0,1 0,4
p/u : 0,1 0,2 0,1 0,1
Sau : 0 0,2 0,1 0,1
a, ----> Sau p/u HCl dư
\(m_{HCldư}=0,2.26,5=7,3\left(g\right)\)
\(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
\(m_{HCl}=\dfrac{200.7,3}{100}=14,6\left(g\right)\)
\(n_{HCl}=\dfrac{14,6}{36,5}=0,4\left(mol\right)\)
b, \(m_{ZnCl_2}=0,1.136=13,6\left(g\right)\)
\(m_{ddZnCl_2}=6,5+200-\left(0,1.2\right)=206,3\left(g\right)\)
\(C\%_{ZnCl_2}=\dfrac{13,6}{206,3}.100\%\approx6,59\%\)
c, \(V_{H_2}=0,1.22,4=2,24\left(l\right)\)
Thể tích H2 thu được thực tế :
\(V_{H_2tt}=2,24.90\%=2,016\left(l\right)\)
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: \(\left\{{}\begin{matrix}n_{CO_2}=n_{BaCl_2}=0,35\left(mol\right)\\n_{HCl\left(dư\right)}=0,1\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{CO_2}=0,35\cdot22,4=7,84\left(l\right)\\C_{M_{BaCl_2}}=\dfrac{0,35}{0,25}=1,4\left(M\right)\\C_{M_{HCl\left(dư\right)}}=\dfrac{0,1}{0,25}=0,4\left(M\right)\end{matrix}\right.\)
Ta có :
nNa2CO3=200.13,25%\106=0,25(mol)
nBaCl2=350.20,8%\208=0,35(mol)
Na2CO3+BaCl2→BaCO3+2NaCl
Ta thấy : nNa2CO3=0,25<nBaCl2=0,35
nên BaCl2dư
Theo phương trình , có :
nBaCl2(pư)=nBaCO3=nNa2CO3=0,25(mol)
nNaCl=2nNa2CO3=0,25.2=0,5(mol)
⇒nBaCl2(dư)=0,35−0,25=0,1(mol)
Sau phản ứng,
mdd=ndd Na2CO3+mdd BaCl2−mBaCO3
=200+350−0,25.197=500,75(gam)
Vậy :
C%BaCl2(dư)=0,1.208\500,75.100%=4,15%
C%NaCl=0,5.58,5\500,75.100%=5,84%
%tk