Đáp án: B

C H 3 C O O H   +   N a O H   →   C H 3 C O O N a   +   H 2 O

Gọi khối lượng dung dịch C H 3 C O O H và NaOH lần lượt là m 1 và m 2 gam

Ta có:  n C H 3 C O O H = m 1 . a 100 . 60 = m 1 . a 6000 m o l ; n N a O H = m 2 . 10 100 . 40 = m 2 400 m o l

Theo phản ứng:  n C H 3 C O O H = n N a O H = n C H 3 C O O N a

⇒ m 1 . a 6000 = m 2 400 ⇒ a = 15 . m 2 m 1 ( 1 )

Dung dịch muối thu được là C H 3 C O O N a

Vì phản ứng không sinh ra kết tủa hay khí bay đi => khối lượng dung dịch thu được sau phản ứng là:

m d d   t r ư ớ c   p ứ   =   m d d   s a u   p ứ   =   m 1   +   m 2

=> 20,5. m 2 = 10,25.( m 1   +   m 2 ) => m 1 = m 2   

Thay vào (1) => a = 15

PTHH: \(CuO+2HCl\rightarrow CuCl_2+H_2O\)

            \(CuCl_2+2KOH\rightarrow2KCl+Cu\left(OH\right)_2\downarrow\)

a+b) Ta có: \(n_{CuO}=\dfrac{8}{80}=0,1\left(mol\right)\)

\(\Rightarrow n_{HCl}=0,2\left(mol\right)=n_{KOH}\) \(\Rightarrow\left\{{}\begin{matrix}C\%_{HCl}=\dfrac{0,2\cdot36,5}{300}\cdot100\%\approx2,43\%\\C_{M_{KOH}}=\dfrac{0,2}{0,2}=1\left(M\right)\end{matrix}\right.\)

c) PTHH: \(Cu\left(OH\right)_2\xrightarrow[]{t^o}CuO+H_2O\)

Theo các PTHH: \(n_{CuO\left(lý.thuyết\right)}=n_{Cu\left(OH\right)_2}=n_{Cu}=0,1\left(mol\right)\)

\(\Rightarrow n_{CuO}=0,1\cdot95\%=0,095\left(mol\right)\) \(\Rightarrow m_{CuO}=0,095\cdot80=7,6\left(g\right)\)

Ok

a, \(m_{CH_3COOH}=100.6\%=6\left(g\right)\Rightarrow n_{CH_3COOH}=\dfrac{6}{60}=0,1\left(mol\right)\)

PT: \(CH_3COOH+NaHCO_3\rightarrow CH_3COONa+CO_2+H_2O\)

Theo PT: \(n_{NaHCO_3}=n_{CH_3COONa}=n_{CO_2}=n_{CH_3COOH}=0,1\left(mol\right)\)

\(\Rightarrow m_{NaHCO_3}=0,1.84=8,4\left(g\right)\)

\(V_{CO_2}=0,1.22,4=2,24\left(l\right)\)

b, Ta có: m _{dd sau pư} = 100 + 8,4 - 0,1.44 = 104 (g)

\(\Rightarrow C\%_{CH_3COONa}=\dfrac{0,1.82}{104}.100\%\approx7,88\%\)

a, \(H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O\)

b, \(n_{KOH}=0,12.0,4=0,048\left(mol\right)\)

Theo PT: \(n_{H_2SO_4}=\dfrac{1}{2}n_{KOH}=0,024\left(mol\right)\)

\(\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,024}{0,08}=0,3\left(M\right)\)

c, \(n_{K_2SO_4}=\dfrac{1}{2}n_{KOH}=0,024\left(mol\right)\)

\(\Rightarrow C_{M_{K_2SO_4}}=\dfrac{0,024}{0,08+0,12}=0,12\left(M\right)\)

Coi 

\(m_{dd\ NaOH} = 100\ gam\\ \Rightarrow n_{NaOH} = \dfrac{100.10\%}{40} = 0,25(mol)\)

CH₃COOH + NaOH → CH₃COONa + H₂O

0,25................0,25.................0,25......................(mol)

\(m_{CH_3COONa} = 0,25.82 = 20,5(gam)\\ \Rightarrow m_{dd\ sau\ pư} = \dfrac{20,5}{10,25\%} = 200(gam)\\ \Rightarrow m_{dd\ axit\ axetic} = 200 -100 = 100(gam)\)

Vậy :

\(C\%_{CH_3COOH} = \dfrac{0,25.60}{100}.100\% = 15\%\)

a, \(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)

\(FeCl_3+3KOH\rightarrow3KCl+Fe\left(OH\right)_{3\downarrow}\)

\(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)

Theo PT: \(n_{HCl}=6n_{Fe_2O_3}=0,6\left(mol\right)\)

\(\Rightarrow m_{HCl}=0,6.36,5=21,9\left(g\right)\)

b, \(n_{Fe\left(OH\right)_3}=n_{FeCl_3}=2n_{Fe_2O_3}=0,2\left(mol\right)\)

\(\Rightarrow m_{Fe\left(OH\right)_3}=0,2.107=21,4\left(g\right)\)

\(n_{KOH}=3n_{FeCl_3}=0,6\left(mol\right)\)

\(\Rightarrow C_{M_{KOH}}=\dfrac{0,6}{0,2}=3\left(M\right)\)

$a\big)$

$n_{CH_3COOH}=\dfrac{100}{1000}.1=0,1(mol)$

$CH_3COOH+NaOH\to CH_3COONa+H_2O$

Theo PT: $n_{NaOH}=n_{CH_3COOH}=0,1(mol)$

$\to C\%_{NaOH}=\dfrac{0,1.40}{50}.100\%=80\%$

$b\big)$

$n_{Na_2CO_3}=\dfrac{10,6}{106}=0,1(mol)$

$2CH_3COOH+Na_2CO_3\to 2CH_3COONa+CO_2+H_2O$

Theo PT: $\begin{cases} n_{CO_2}=n_{Na_2CO_3}=0,1(mol)\\ n_{CH_3COONa}=2n_{Na_2CO_3}=0,2(mol) \end{cases}$

$\to C\%_{CH_3COONa}=\dfrac{0,2.82}{60+10,6-0,1.44}.100\%\approx 24,77\%$

\(A.Fe+2HCl\rightarrow FeCl_2+H_2\\ B.n_{Fe}=\dfrac{11,2}{56}=0,2mol\\ n_{FeCl_2}=n_{Fe}=0,2mol\\ C_{M_{FeCl_2}}=\dfrac{0,2}{0,1}=2M\\ C.n_{HCl}=2.0,2=0,4mol\\ C_{M_{HCl}}=\dfrac{0,4}{0,1}=4M\)