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a, \(n_{CO_2}=\dfrac{0,56}{22,4}=0,025\left(mol\right)\)
PT: \(2CH_3COOH+Na_2CO_3\rightarrow2CH_3COONa+CO_2+H_2O\)
Theo PT: \(n_{CH_3COOH}=2n_{CO_2}=0,05\left(mol\right)\)
\(\Rightarrow C\%_{CH_3COOH}=\dfrac{0,05.60}{100}.100\%=3\%\)
b, Theo PT: \(n_{Na_2CO_3}=n_{CO_2}=0,025\left(mol\right)\Rightarrow m_{Na_2CO_3}=0,025.106=2,65\left(g\right)\)
\(n_{CH_3COONa}=2n_{CO_2}=0,05\left(mol\right)\Rightarrow m_{CH_3COONa}=0,05.82=4,1\left(g\right)\)
c, \(C_2H_5OH+O_2\underrightarrow{^{mengiam}}CH_3COOH+H_2O\)
Theo PT: \(n_{C_2H_5OH\left(LT\right)}=n_{CH_3COOH}=0,05\left(mol\right)\)
Mà: H = 80%
\(\Rightarrow n_{C_2H_5OH\left(TT\right)}=\dfrac{0,05}{80\%}=0,0625\left(mol\right)\)
\(\Rightarrow m_{C_2H_5OH\left(TT\right)}=0,0625.46=2,875\left(g\right)\)
\(\Rightarrow V_{C_2H_5OH}=\dfrac{2,875}{0,8}=3,59375\left(ml\right)\)
\(\Rightarrow V_{C_2H_5OH\left(10^o\right)}=\dfrac{3,59375}{10}.100=35,9375\left(ml\right)\)
a. \(m_{C_2H_5OH}=\dfrac{10.0,8.8}{100}=0,64\left(kg\right)\)
\(n_{C_2H_5OH}=\dfrac{0,64}{46}=\dfrac{8}{575}\left(k-mol\right)\)
\(C_2H_5OH+O_2\rightarrow\left(t^o,men.giấm\right)CH_3COOH+H_2O\)
\(\dfrac{8}{575}\) \(\dfrac{8}{575}\) ( k-mol )
\(m_{CH_3COOH}=\dfrac{8}{575}.60.92\%=0,768\left(kg\right)=768\left(g\right)\)
b.\(m_{dd_{CH_3COOH}}=\dfrac{768.100}{4}=19200\left(g\right)\)
Ta có:
\(V_{C2H5OH}=4,6.14\%=0,644\left(l\right)=644\left(ml\right)\)
\(\Rightarrow m_{C2H5OH}=0,8.644=515,2\left(g\right)\)
\(\Rightarrow n_{C2H5OH}=\frac{515,2}{46}=11,2\left(mol\right)\)
\(V_{H2O}=4,6-0,644=3,956\left(l\right)=3956\left(ml\right)\)
\(\Rightarrow m_{H2O}=3956\left(g\right)\)
Mà H = 30%
\(\Rightarrow n_{C2H5OH\left(pư\right)}=11,2.30\%=3,36\left(mol\right)\)
\(C_2H_5OH+O_2\underrightarrow{^{men.giam}}CH_3COOH+H_2O\)
\(\Rightarrow n_{O2}=n_{CH3COOH}=3,36\left(mol\right)\)
\(m_{dd\left(spu\right)}=515,2+3956+3,36.32=4578,72\left(g\right)\)
\(\Rightarrow C\%_{CH3COOH}=\frac{3,36.60}{4578,72}.100\%=4,4\%\)
Đáp án: C
Giấm ăn là dung dịch axit axetic có nồng độ phần trăm từ 2-5%
a)
$C_2H_5OH + O_2 \xrightarrow{men\ giấm} CH_3COOH + H_2O$
V rượu = 57,5.12/100 = 6,9(lít) = 6900(cm3)
=> m rượu = 6900.0,8 = 5520(gam)
Theo PTHH :
n CH3COOH = n C2H5OH = 5520/46 = 120(mol)
m CH3COOH = 120.60 = 7200(gam)
b)
m dd giấm = 7200/4% = 180 000(gam)
\(V_r=57.5\cdot0.12=6.9\left(l\right)\)
\(m_{C_2H_5OH}=6.9\cdot0.8=5.52\left(g\right)\)
\(n_{C_2H_5OH}=\dfrac{5.52}{46}=0.12\left(mol\right)\)
\(n_{C_2H_5OH\left(pư\right)}=0.12\cdot92\%=0.1104\left(mol\right)\)
\(C_2H_5OH+O_2\underrightarrow{mg}CH_3COOH+H_2O\)
\(0.1104........................0.1104\)
\(m_{dd_{CH_3COOH}}=\dfrac{0.1104\cdot60}{4\%}=165.6\left(g\right)\)
Đáp án: B
Ta có: V g i ấ m ă n = 1 lít = 1000 ml
=> khối lượng giấm ăn là:
m g i ấ m ă n = V g i ấ m ă n . D g i ấ m ă n =1000.1,01=1010 gam
Mà trong dung dịch giấm ăn nồng độ axit axetic từ 2-5%
=> khối lượng axit axetic là: 1010.2% ≤ m g i ấ m ă n ≤ 1010.5%
=> 20 , 2 ≤ m g i ấ m ă n ≤ 50 , 5 g a m
Xét 4 đáp án chỉ có 20,2 gam thỏa mãn