Câu 8 : 

\(n_{MgCO3}=\dfrac{42}{84}=0,5\left(mol\right)\)

Pt : \(2CH_3COOH+MgCO_3\rightarrow\left(CH_3COO\right)_2Mg+CO_2+H_2O\)

                 1                  0,5                                         0,5

a) \(V_{CO2\left(dktc\right)}=0,5.22,4=11,2\left(l\right)\)

b) \(V_{CH3COOH}=\dfrac{1}{2}=0,5\left(l\right)\)

c) Pt : \(CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O\)

                  1                                         1

300ml = 0,3l

\(C_{MCH3COONa}=\dfrac{1}{0,3}=\dfrac{10}{3}\left(M\right)\)

 Chúc bạn học tốt

a) \(CaO+2HCl\rightarrow CaCl_2+H_2O\)

\(HCl+NaOH\rightarrow NaCl+H_2O\)

b) \(n_{CaO}=\dfrac{2,8}{56}=0,05\left(mol\right);n_{NaOH}=\dfrac{100.4\%}{40}=0,1\left(mol\right)\)

\(m_{muối}=m_{CaCl_2}+m_{NaCl}=0,05.111+0,1.58,5=11,4\left(g\right)\)

c) \(CM_{HCl}=\dfrac{0,05.2+0,1}{0,5}=0,4M\)

a) \(m_{HCl}=\dfrac{200.10,95}{100}=21,9\left(g\right)\)

=> \(n_{HCl}=\dfrac{21,9}{36,5}=0,6\left(mol\right)\)

b) \(n_{CaCO_3}=\dfrac{a}{100}=0,01a\left(g\right)\)

\(n_{NaOH}=0,05.2=0,1\left(mol\right)\)

PTHH: CaCO₃ + 2HCl --> CaCl₂ + CO₂ + H₂O

______0,01a---->0,02a---->0,01a->0,01a___________(mol)

NaOH + HCl --> NaCl + H₂O

_0,1----->0,1___________________________________(mol)

=> 0,02a = 0,6 - 0,1

=> a = 25 (g)

c) \(V_{CO_2}=0,01.25.22,4=5,6\left(l\right)\)

d) \(\left\{{}\begin{matrix}C\%\left(CaCl_2\right)=\dfrac{0,25.111}{25+200-0,25.44}.100\%=12,97\%\\C\%\left(HCl_{dư}\right)=\dfrac{0,1.36,5}{25+200-0,25.44}.100\%=1,705\%\end{matrix}\right.\)

a) \(PT:CaCO_3+2HCl\rightarrow CaCl_2+H_2O+CO_2\uparrow\)

\(HCl+NaOH\rightarrow NaOH+H_2O\)

b) \(m_{HCl}=\frac{200.10,95\%}{100\%}=21,9\left(g\right)\)

\(n_{HCl}=\frac{21,9}{36,5}=0,6\left(mol\right)\)

c) \(n_{NaOH}=2.0,05=0,1\left(mol\right)\Rightarrow n_{HCl\left(pưNaOH\right)}=0,1\left(mol\right)\)

\(\Rightarrow n_{HCl\left(pưCaCO_3\right)}=0,6-0,1=0,5\left(mol\right)\)

d) \(n_{CaCO_3}=\frac{1}{2}n_{HCl\left(pưCaCO_3\right)}=0,5.\frac{1}{2}=0,25\left(mol\right)\)

\(m_{CaCO_3}=0,25.100=25\left(g\right)\)

e) \(n_{CO_2}=n_{CaCO_3}=0,25\left(mol\right)\)

\(V_{CO_2}=0,25.22,4=5,6\left(l\right)\)

f) \(n_{CaCl_2}=n_{CaCO_3}=0,25\left(mol\right)\)

\(m_{ddA}=25+200-0,25.44=214\left(g\right)\)

\(C\%_{ddCaCl_2}=\frac{0,25.111}{214}.100\%=12,97\%\)

\(C\%_{ddHCldư}=\frac{0,1.36,5}{214}.100\%=1,71\%\)

2CH3COOH+Mg->(CH3COO)2Mg+H2

0,02---------------0,01-------0,01----------0,01

n muối=0,01mol

=>CM=\(\dfrac{0,02}{0,04}=0,5M\)

=>VH2=0,01.22,4=0,224l

CH3COOH+NaOH->CH3COONa+H2O

0,02--------------0,02

=>VNaOH=\(\dfrac{0,02}{0,75}=0,03l\)

a) \(n_{\left(CH_3COO\right)_2Mg}=\dfrac{1,42}{142}=0,01\left(mol\right)\)

PTHH: Mg + 2CH₃COOH --> (CH₃COO)₂Mg + H₂

           0,01<-------0,02<------------0,01------->0,01

=> \(C_{M\left(dd.CH_3COOH\right)}=\dfrac{0,02}{0,04}=0,5M\)

b) V_H2 = 0,01.22,4 = 0,224 (l)

c) 

PTHH: NaOH + CH₃COOH --> CH₃COONa + H₂O

             0,02<------0,02

=> \(V_{dd.NaOH}=\dfrac{0,02}{0,75}=\dfrac{2}{75}\left(l\right)=\dfrac{80}{3}\left(ml\right)\)

\(a.2CH_3COOH+Mg\rightarrow\left(CH_3COO\right)_2Mg+H_2\\ n_{\left(CH_3COO\right)_2Mg}=0,01\left(mol\right)\\ n_{CH_3COOH}=2n_{\left(CH_3COO\right)_2Mg}=0,02\left(mol\right)\\ \Rightarrow CM_{CH_3COOH}=\dfrac{0,02}{0,04}=0,5M\\ b.n_{H_2}=n_{\left(CH_3COO\right)_2Mg}=0,01\left(mol\right)\\ \Rightarrow V_{H_2}=0,01.22,4=0,224\left(l\right)\\ c.CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O\\ n_{CH_3COOH}=n_{NaOH}=0,02\left(mol\right)\\ \Rightarrow V_{NaOH}=\dfrac{0,02}{0,75}=0,02667\left(l\right)=26,67ml\)

a, \(2Na+2H_2O\rightarrow2NaOH+H_2\)

Ta có: \(n_{Na}=\dfrac{2,3}{23}=0,1\left(mol\right)\)

\(n_{H_2O}=\dfrac{200}{18}=\dfrac{100}{9}\left(mol\right)\)

Xét tỉ lệ: \(\dfrac{0,1}{2}< \dfrac{\dfrac{100}{9}}{2}\), ta được H₂O dư.

Theo PT: \(n_{H_2}=\dfrac{1}{2}n_{Na}=0,05\left(mol\right)\Rightarrow V_{H_2}=0,05.22,4=1,12\left(l\right)\)

b, Theo PT: \(n_{NaOH}=n_{Na}=0,1\left(mol\right)\)

Ta có: m _{dd sau pư} = 2,3 + 100 - 0,05.2 = 102,2 (g)

\(\Rightarrow C\%_{NaOH}=\dfrac{0,1.40}{102,2}.100\%\approx3,91\%\)

c, - Dung dịch làm quỳ tím hóa xanh.

\(n_{Na}=\dfrac{2,3}{23}=0,1\left(mol\right)\\ 2Na+2H_2O\rightarrow2NaOH+H_2\\ n_{H_2}=\dfrac{0,1}{2}=0,05\left(mol\right);n_{NaOH}=n_{Na}=0,1\left(mol\right)\\ a,V=V_{H_2\left(đktc\right)}=0,05.22,4=1,12\left(l\right)\\ b,m_{ddNaOH}=m_{Na}+m_{H_2O}-m_{H_2}=2,3+200-0,05.2=202,2\left(g\right)\\ C\%_{ddNaOH}=\dfrac{40.0,1}{202,2}.100\approx1,978\%\\ c,NaOH-Tính.bazo\Rightarrow Quỳ.tím.hoá.xanh\)

a)

$Fe + H_2SO_4 \to FeSO_4 + H_2$
$n_{H_2SO_4} = n_{H_2} = n_{Fe} = \dfrac{16,8}{56} = 0,3(mol)$

$V = 0,3.22,4 = 6,72(lít)$
$C_{M_{H_2SO_4}} = \dfrac{0,3}{0,25} = 1,2M$

b)

$n_{CuO} = \dfrac{16}{80} = 0,2(mol)$
$CuO + H_2 \xrightarrow{t^o} Cu + H_2O$
$n_{CuO} < n_{H_2}$ nên $H_2$ dư

$n_{Cu} = n_{CuO} = 0,2(mol)$
$m_{Cu} = 0,2.64 = 12,8(gam)$

\(n_{Fe}=\dfrac{m}{M}=\dfrac{16,8}{56}=0,3\left(mol\right)\\ PT:Fe+H_2SO_4\rightarrow FeSO_4+H_2\)

       0,3     0,3                        0,3 (mol)

a) V= n. 22,4 = 0,3 . 22,4 = 6,72(l)

 \(C\%=\dfrac{m_{H_2SO_4}}{m_{dd}}.100\%=\dfrac{0,3.98}{200}.100\%=11,76\%\)

b) PT: \(H_2+CuO\underrightarrow{t^o}Cu+H_2O\)

         0,3                0,3 

=> m_Cu=n.M=0,3.64=19,2(g)