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Khối lượng dung dịch NaHCO3:
CH3COOH + NaHCO3 → CH3COONa + CO2 + H2O
nCH3COOH = 12 / 60 = 0,2 mol.
nNaHCO3 = 0,2mol.
mNaHCO3 cần dùng = 0,2 x 84 = 16,8g.
Khối lượng dung dịch NaHCO3 cần dùng: 16,8 x 100 / 8,4 = 200g.
a)
$CH_3COOH + NaHCO_3 \to CH_3COONa + CO_2 + H_2O$
b)
n NaHCO3 = n CH3COOH = 100.12%/60 = 0,2(mol)
m dd NaHCO3 = 0,2.84/8% = 210(gam)
c)
n CO2 = n CH3COOH = 0,2(mol)
=> V CO2 = 0,2.22,4 = 4,48(lít)
d)
m dd = m dd CH3COOH + m dd NaHCO3 - m CO2 = 100 + 210 - 0,2.44 = 301,2(gam)
C% CH3COONa = 0,2.82/301,2 .100% = 5,44%
\(m_{CH_3COOH}=\dfrac{80.9}{100}=7,2\left(g\right)\)
\(n_{CH_3COOH}=\dfrac{7,2}{60}=0,12\left(mol\right)\)
PTHH :
\(15CH_3COOH+10NaHCO_3\rightarrow10CH_3COONa+2H_2O+20CO_2\uparrow\)
0,12 0,08 0,08 0,016 0,16
\(a,m_{NaHCO_3}=84.0,08=6,72\left(g\right)\)
\(m_{ddNaHCO_3}=\dfrac{6,72.100}{4,2}=160\left(g\right)\)
\(b,m_{CH_3COONa}=0,08.82=6,56\left(g\right)\)
\(m_{H_2O}=0,016.18=0,288\left(g\right)\)
\(m_{CO_2}=0,16.44=7,04\left(g\right)\)
\(m_{ddCH_3COONa}=80+160-0,288-7,04=232,672\left(g\right)\)
\(C\%=\dfrac{6,56}{232,672}\approx2,82\%\)
Ta có: \(m_{CH_3COOH}=100.12\%=12\left(g\right)\Rightarrow n_{CH_3COOH}=\dfrac{12}{60}=0,2\left(mol\right)\)
PT: \(CH_3COOH+NaHCO_3\rightarrow CH_3COONa+CO_2+H_2O\)
Theo PT: \(n_{NaHCO_3}=n_{CH_3COONa}=n_{CO_2}=n_{CH_3COOH}=0,2\left(mol\right)\)
\(\Rightarrow m_{ddNaHCO_3}=\dfrac{0,2.84}{8,4\%}=200\left(g\right)\)
Ta có: m dd sau pư = m dd CH3COOH + m dd NaHCO3 - mCO2 = 100 + 200 - 0,2.44 = 291,2 (g)
\(\Rightarrow C\%_{CH_3COONa}=\dfrac{0,2.82}{291,2}.100\%\approx2,82\%\)
\(m_{NaOH}=\dfrac{200\cdot8}{100}=16\left(g\right)\Rightarrow n_{NaOH}=\dfrac{16}{40}=0,4mol\)
\(NaOH+HCl\rightarrow NaCl+H_2O\)
0,4 0,4 0,4 0,4
a)\(m_{HCl}=0,4\cdot36,5=14,6\left(g\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{14,6}{7,3}\cdot100=200\left(g\right)\)
b)\(m_{NaCl}=0,4\cdot58,5=23,4\left(g\right)\)
\(m_{H_2O}=0,4\cdot18=7,2\left(g\right)\)
\(m_{ddsau}=200+200-7,2=392,8\left(g\right)\)
\(\Rightarrow C\%=\dfrac{23,4}{392,8}\cdot100=5,96\%\)
c) \(n_{SO_2}=\dfrac{6,72}{22,4}=0,3mol\)
\(2NaOH+SO_2\rightarrow Na_2SO_4+H_2O\)
0,4 0,3 0,3 0,3
\(m_{Na_2SO_4}=0,3\cdot142=42,6\left(g\right)\)
Ta có: \(n_{NaOH}=0,1.0,5=0,05\left(mol\right)\)
PT: \(CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O\)
Theo PT: \(n_{CH_3COOH}=n_{CH_3COONa}=n_{NaOH}=0,05\left(mol\right)\)
a, \(C_{M_{CH_3COOH}}=\dfrac{0,05}{0,2}=0,25\left(M\right)\)
b, \(m_{CH_3COONa}=0,05.82=4,1\left(g\right)\)
nC2H4 = 0.56/22.4 = 0.025 (mol)
C2H4 + Br2 => C2H4Br2
0.025__0.025____0.025
mC2H4Br2 = 0.025*188 = 4.7 (g)
mBr2 = 0.025*160 = 4 (g)
C% Br2 = 4/150 * 100% = 2.67%
\(n_{Na_2SO_3}=\dfrac{12,6}{126}=0,1mol\)
\(Na_2SO_3+H_2SO_4\rightarrow Na_2SO_4+SO_2+H_2O\)
a) \(n_{SO_2}=n_{Na_2SO_3}=0,1mol\) \(\Rightarrow V=2,24l\)
b) \(n_{H_2SO_4}=n_{Na_2SO_3}=0,1mol\) \(\Rightarrow C_M=\dfrac{0,1}{0,2}=0,5M\)
c) \(m_{Na_2SO_4}=0,1\cdot142=14,2g\)