Cho dd CH3COOH 15% tác dụng vừa đủ với dd Ca(OH)2 a% thu được dd muối có nồng độ 9,875%. Tìm a.
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a)
\(n_{CO_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
PTHH: Na2CO3 + 2CH3COOH --> 2CH3COONa + CO2 + H2O
0,15<---------0,3<------------------------0,15
=> \(C\%_{dd.CH_3COOH}=\dfrac{0,3.60}{200}.100\%=9\%\)
b)
\(m_{dd.Na_2CO_3}=\dfrac{0,15.106.100}{15}=106\left(g\right)\)
c)
PTHH: 2CH3COOH + Ba(OH)2 --> (CH3COO)2Ba + 2H2O
0,3--------->0,15
=> \(V_{dd.Ba\left(OH\right)_2}=\dfrac{0,15}{0,5}=0,3\left(l\right)=300\left(ml\right)\)
\(m_{CH_3COOH}=\dfrac{80.9}{100}=7,2\left(g\right)\)
\(n_{CH_3COOH}=\dfrac{7,2}{60}=0,12\left(mol\right)\)
PTHH :
\(15CH_3COOH+10NaHCO_3\rightarrow10CH_3COONa+2H_2O+20CO_2\uparrow\)
0,12 0,08 0,08 0,016 0,16
\(a,m_{NaHCO_3}=84.0,08=6,72\left(g\right)\)
\(m_{ddNaHCO_3}=\dfrac{6,72.100}{4,2}=160\left(g\right)\)
\(b,m_{CH_3COONa}=0,08.82=6,56\left(g\right)\)
\(m_{H_2O}=0,016.18=0,288\left(g\right)\)
\(m_{CO_2}=0,16.44=7,04\left(g\right)\)
\(m_{ddCH_3COONa}=80+160-0,288-7,04=232,672\left(g\right)\)
\(C\%=\dfrac{6,56}{232,672}\approx2,82\%\)
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%
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, \(m_{CH_3COONa}=0,05.82=4,1\left(g\right)\)
Giả sử có 100g dd CH3COOH 15%
Ta có:
\(n_{CH3COOH}=\frac{100.15\%}{60}=0,25\left(mol\right)\)
\(PTHH:Ca\left(OH\right)_2+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Ca+2H_2O\)
\(\Rightarrow n_{Ca\left(OH\right)2}=n_{\left(CH3COO\right)2Ca}=0,125\left(mol\right)\)
\(\Rightarrow m_{dd\left(Ca\left(OH\right)2\right)}=\frac{0,125.74}{x\%}=\frac{9,25}{x\%}\)
\(\Rightarrow m_{dd\left(spu\right)}=\frac{9,25}{x\%+100}\Leftrightarrow C\%=9,875\%\)
\(\frac{0,125.158.100}{\frac{9,25}{x\%+100}}=9,875\Leftrightarrow x=9,25\)
\(n_{CO_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)
PT: \(CO_2+Ca\left(OH\right)_2\rightarrow CaCO_3+H_2O\)
Theo PT: \(n_{Ca\left(OH\right)_2}=n_{CaCO_3}=n_{CO_2}=0,25\left(mol\right)\)
a, \(C_{M_{Ca\left(OH\right)_2}}=\dfrac{0,25}{0,1}=2,5\left(M\right)\)
b, \(m_{CaCO_3}=0,25.100=25\left(g\right)\)
c, \(Ca\left(OH\right)_2+2HCl\rightarrow CaCl_2+2H_2O\)
Theo PT: \(n_{HCl}=2n_{Ca\left(OH\right)_2}=0,5\left(mol\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{0,5.36,5}{20\%}=91,25\left(g\right)\)
Gọi nNa2CO3 = x (mol)
Na2CO3 + 2HCl \(\rightarrow\) 2NaCl + H2O + CO2
x \(\rightarrow\) 2x \(\rightarrow\) 2 x (mol)
C%(NaCl) = \(\frac{2.58,5x}{200+120}\) . 100% = 20%
=> x =0,547 (mol)
mNa2CO3 = 0,547 . 106 = 57,982 (g)
mHCl = 2 . 0,547 . 36,5 =39,931 (g)
C%(Na2CO3) =\(\frac{57,892}{200}\) . 100% = 28,946%
C%(HCl) = \(\frac{39,931}{120}\) . 100% = 33,28%
Giả sử có 100g dd CH3COOH 15%
Ta có:
nCH3COOH=\(\dfrac{100.15\%}{60}\)=0,25(mol)
PTHH:Ca(OH)2+2CH3COOH→(CH3COO)2Ca+2H2O
⇒nCa(OH)2=n(CH3COO)2Ca=0,125(mol)
⇒mdd(Ca(OH)2)=\(\dfrac{0,125.74}{X\%}\)=9,25
⇒mdd(spu)=\(\dfrac{9,25}{X\%+100}\)⇔C%=9,875%
\(\dfrac{0,125.158.100}{\dfrac{9,25}{X\%+100}}\)=9,875⇔x=9,25