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Bài 7:
Ta có: \(\left\{{}\begin{matrix}n_{CO_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\\n_{NaOH}=0,2\cdot1=0,2\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\) Tạo 2 muối
PTHH: \(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)
a_______2a__________a (mol)
\(CO_2+NaOH\rightarrow NaHCO_3\)
b_______b__________b (mol)
Ta lập HPT: \(\left\{{}\begin{matrix}a+b=0,15\\2a+b=0,2\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=0,05\\b=0,1\end{matrix}\right.\)
Mặt khác: \(m_{dd}=m_{CO_2}+m_{ddNaOH}=0,15\cdot44+200\cdot1,25=256,6\left(g\right)\)
\(\Rightarrow\left\{{}\begin{matrix}C\%_{Na_2CO_3}=\dfrac{0,05\cdot106}{256,6}\cdot100\%\approx2,1\%\\C\%_{NaHCO_3}=\dfrac{0,1\cdot72}{256,6}\cdot100\%\approx2,8\%\end{matrix}\right.\)
Bài 8:
PTHH: \(RCO_3+2HNO_3\rightarrow R\left(NO_3\right)_2+CO_2\uparrow+H_2O\)
Giả sử \(n_{RCO_3}=1\left(mol\right)\) \(\Rightarrow\left\{{}\begin{matrix}n_{HNO_3}=2\left(mol\right)\\n_{R\left(NO_3\right)_2}=1\left(mol\right)=n_{CO_2}\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}m_{ddHNO_3}=\dfrac{2\cdot63}{20\%}=630\left(g\right)\\m_{R\left(NO_3\right)_2}=R+124\left(g\right)\\m_{CO_2}=44\left(g\right)\end{matrix}\right.\) \(\Rightarrow C\%_{R\left(NO_3\right)_2}=\dfrac{124+R}{R+60+630-44}=0,26582\)
\(\Leftrightarrow R=65\) (Kẽm) \(\Rightarrow\) CTHH của muối cacbonat là ZnCO3
300ml = 0,3l
\(n_{HNO3}=1.0,3=0,3\left(mol\right)\)
Pt : \(NaOH+HNO_3\rightarrow NaNO_3+H_2O|\)
1 1 1 1
0,3 0,3 0,3
\(n_{NaOH}=\dfrac{0,3.1}{1}=0,3\left(mol\right)\)
200ml = 0,2l
\(C_{M_{NaOH}}=\dfrac{0,3}{0,2}=1,5\left(M\right)\)
\(n_{NaNO3}=\dfrac{0,3.1}{1}=0,3\left(mol\right)\)
⇒ \(m_{NaNO3}=0,3.85=25,5\left(g\right)\)
Sau phản ứng :
\(V_{dd}=0,2+0,3=0,5\left(l\right)\)
\(C_{M_{NaNO3}}=\dfrac{0,3}{0,5}=0,6\left(M\right)\)
Chúc bạn học tốt
\(n_{HNO_3}=0,3\left(mol\right)\)
\(NaOH+HNO_3\rightarrow NaNO_3+H_2O\)
Theo PT: \(n_{NaOH}=n_{NaNO_3}=n_{HNO_3}=0,3\left(mol\right)\)
\(\Rightarrow CM_{NaOH}=\dfrac{0,3}{0,2}=1,5M\)
\(m_{NaNO_3}=0,3.85=25,5\left(g\right)\)
a, \(H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\)
b, \(n_{H_2SO_4}=0,2.1,5=0,3\left(mol\right)\)
Theo PT: nNa2SO4 = nH2SO4 = 0,3 (mol) ⇒ mNa2SO4 = 0,3.142 = 42,6 (g)
nNaOH = 2nH2SO4 = 0,6 (mol) ⇒ mNaOH = 0,6.40 = 24 (g)
c, \(n_{CO_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\)
\(\Rightarrow\dfrac{n_{NaOH}}{n_{CO_2}}=\dfrac{0,6}{0,4}=1,5\) → Pư tạo NaHCO3 và Na2CO3.
PT: \(2NaOH+CO_2\rightarrow Na_2CO_3+H_2O\)
\(NaOH+CO_2\rightarrow NaHCO_3\)
\(n_{H_2SO_4}=1.0,2=0,2(mol)\\ PTHH:2NaOH+H_2SO_4\to Na_2SO_4+2H_2O\\ a,n_{NaOH}=0,4(mol);n_{Na_2SO_4}=0,2(mol)\\ \Rightarrow \begin{cases} m_{Na_2SO_4}=0,2.142=28,4(g)\\ m_{dd_{NaOH}}=\dfrac{0,4.40}{20\%}=80(g) \end{cases}\\ b,2KOH+H_2SO_4\to K_2SO_4+2H_2O\\ \Rightarrow n_{KOH}=0,4(mol)\\ \Rightarrow m_{dd_{KOH}}=\dfrac{0,4.56}{5,6\%}=400(g)\\ \Rightarrow V_{dd_{KOH}}=\dfrac{400}{1,045}=382,78(ml)\)
Bước 1: nH2SO4 = VH2SO4 . CM H2SO4= 0,2 . 1 = 0,2mol
Bước 2:
PTHH: 2NaOH + H2SO4 → Na2SO4 + H2O
2 mol 1 mol
? mol 0,2mol
nNaOH=0,2.21=0,4mol.nNaOH=0,2.21=0,4mol.
m NaOH= n NaOH.MNaOH = 0,4 . (23 + 16 + 1) = 16g
Bước 3: C% = mNaOH : m dd NaOH => mdd NaOH = mNaOH : C% = 16 : 20% = 80g
a) PTHH: \(K_2O+H_2O\rightarrow2KOH\)
Ta có: \(n_{KOH}=2n_{K_2O}=2\cdot\dfrac{35,25}{94}=0,75\left(mol\right)\)
\(\Rightarrow C_{M_{KOH}}=\dfrac{0,75}{0,75}=1\left(M\right)\)
b) Ta có: \(\left\{{}\begin{matrix}n_{KOH}=0,75\left(mol\right)\\n_{CO_2}=\dfrac{8,4}{22,4}=0,375\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\) Tạo muối trung hòa
PTHH: \(CO_2+2KOH\rightarrow K_2CO_3+H_2O\)
Theo PTHH: \(n_{K_2CO_3}=0,375\left(mol\right)\) \(\Rightarrow m_{K_2CO_3}=0,375\cdot138=51,75\left(g\right)\)
c) PTHH: \(2KOH+H_2SO_4\rightarrow K_2SO_4+2H_2O\)
Theo PTHH: \(n_{H_2SO_4}=0,375\left(mol\right)\)
\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,375\cdot98}{60\%}=61,25\left(g\right)\) \(\Rightarrow V_{ddH_2SO_4}=\dfrac{61,25}{1,5}\approx40,83\left(ml\right)\)
Cảm ơn mấy bạn rất nhiều❤🖒chúc mấy bạn ngày mới vui vẻ
a) \(n_{CO_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
PTHH: CO2 + 2NaOH → Na2CO3 + H2O
Mol: 0,15 0,3 0,15
\(C_{M_{ddNaOH}}=\dfrac{0,3}{0,2}=1,5M\)
b) Na2CO3: natri cacbonat
\(m_{Na_2CO_3}=0,15.106=15,9\left(g\right)\)
c)
PTHH: 2NaOH + H2SO4 → Na2SO4 + 2H2O
Mol: 0,15 0,075
\(V_{ddH_2SO_4}=\dfrac{0,075}{1}=0,075\left(l\right)=75\left(ml\right)\)