a) $CuSO_4 + 2NaOH \to Cu(OH)_2 + Na_2SO_4$

b) $n_{Cu(OH)_2} = n_{CuSO_4} = \dfrac{16}{160} = 0,1(mol)$
$m_{Cu(OH)_2} = 0,1.98 = 9,8(gam)$

c) $n_{NaOH} = 2n_{CuSO_4} = 0,2(mol) \Rightarrow C_{M_{NaOH}} = \dfrac{0,2}{0,1} = 2M$

PTHH: \(CuSO_4+2NaOH\rightarrow Na_2SO_4+Cu\left(OH\right)_2\downarrow\)

Ta có: \(n_{CuSO_4}=\dfrac{16}{160}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{NaOH}=0,2\left(mol\right)\\n_{Cu\left(OH\right)_2}=0,1\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}C_{M_{NaOH}}=\dfrac{0,2}{0,1}=2\left(M\right)\\m_{Cu\left(OH\right)_2}=0,1\cdot98=9,8\left(g\right)\end{matrix}\right.\)

a, \(n_{Cu\left(OH\right)_2}=\dfrac{0,49}{98}=0,005\left(mol\right)\)

Chất kết tủa là Cu(OH)₂

PTHH: 2NaOH + CuSO₄ → Na₂SO₄ + Cu(OH)₂ ↓

Mol:       0,01                                            0,005

b, \(C_{M_{ddNaOH}}=\dfrac{0,01}{0,02}=0,5M\)

\(2NaOH+CuSO_4\rightarrow Na_2SO_4+Cu\left(OH\right)_2\downarrow\)

Kết tủa thu được: \(Cu\left(OH\right)_2\downarrow\)

\(n_{Cu\left(OH\right)_2}=\dfrac{0,49}{98}=0,005mol\)

\(\Rightarrow n_{NaOH}=2n_{Cu\left(OH\right)_2}=2\cdot0,005=0,01mol\)

\(C_M=\dfrac{0,01}{\dfrac{20}{1000}}=0,5M\)

a, PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\)

\(MgCl_2+2NaOH\rightarrow2NaCl+Mg\left(OH\right)_{2\downarrow}\)

\(Mg\left(OH\right)_2\underrightarrow{t^o}MgO+H_2O\)

b, Ta có: \(n_{Mg}=\dfrac{9,6}{24}=0,4\left(mol\right)\)

Theo PT: \(n_{HCl}=2n_{Mg}=0,8\left(mol\right)\)

\(\Rightarrow C_{M_{HCl}}=\dfrac{0,8}{0,2}=4\left(M\right)\)

c, Theo PT: \(n_{MgO}=n_{Mg}=0,4\left(mol\right)\)

\(\Rightarrow m_{MgO}=0,4.40=16\left(g\right)\)

a) NaOH + HCl --> NaCl + H2O

b) Số mol NaOH là: n(NaOH) = 0,15mol

Theo pthh thì số mol NaCl là: n(NaCl) = 0,15mol

Khối lượng NaCl là: 0,15.58,5 = 8,775g

c)theo pthh thì số mol HCl là: 0,15mol

V(ddHCl)=100ml=0,1l

Nồng độ mol ddHCl là:

0,15/0,1=1,5M

\(PTHH:Fe+CuSO_4\)→\(FeSO_4+Cu\)

\(+n_{Fe}=\dfrac{16,8}{56}=0,3\left(mol\right)\)

Theo PTHH ta có: 

\(+n_{Cu}=n_{Fe}=0,3\left(mol\right)\)

\(+m_{Cu}=0,3.64=19,2\left(gam\right)\)

\(+n_{CuSO_4}=n_{Fe}=0,3\left(mol\right)\)

\(+V_{CuSO_4}=0,3.0,5=0,15\left(lit\right)\)

d)

PTHH:  \(2NaOH+CuSO_4\) →\(Cu\left(OH\right)_2\downarrow+Na_2SO_4\)

Cu(OH)₂ làm quỳ tím chuyển màu xanh vì là bazo.

\(n_{CO_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)

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: \(n_{HCl}=2n_{Ca\left(OH\right)_2}=0,5\left(mol\right)\)

\(\Rightarrow m_{ddHCl}=\dfrac{0,5.36,5}{20\%}=91,25\left(g\right)\)

a) PTHH: \(FeCl_3+3NaOH\rightarrow3NaCl+Fe\left(OH\right)_3\downarrow\)

                 \(2Fe\left(OH\right)_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+6H_2O\)

b) Ta có: \(n_{FeCl_3}=0,3\cdot0,5=0,15\left(mol\right)\)

\(\Rightarrow n_{NaOH}=0,45mol\) \(\Rightarrow V_{ddNaOH}=\dfrac{0,45}{0,25}=1,8\left(l\right)\)

c) Theo PTHH: \(n_{NaCl}=n_{NaOH}=0,45mol\)

\(\Rightarrow C_{M_{NaCl}}=\dfrac{0,45}{2,1}\approx0,21\left(M\right)\) 

(Coi như thể tích dd thay đổi không đáng kể)

d) Theo PTHH: \(n_{H_2SO_4}=\dfrac{3}{2}n_{Fe\left(OH\right)_3}=\dfrac{3}{2}n_{FeCl_3}=0,225mol\)

\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,225\cdot98}{20\%}=110,25\left(g\right)\) 

\(\Rightarrow V_{ddH_2SO_4}=\dfrac{110,25}{1,14}\approx96,71\left(ml\right)\)

\(n_{FeCl_3}=0.2\cdot0.4=0.08\left(mol\right)\)

\(FeCl_3+3NaOH\rightarrow Fe\left(OH\right)_3+3NaCl\)

\(0.08...........0.24..............0.08\)

\(2Fe\left(OH\right)_3\underrightarrow{^{^{t^0}}}Fe_2O_3+3H_2O\)

\(0.08...........0.04\)

\(m_{Fe_2O_3}=0.04\cdot160=6.4\left(g\right)\)

\(V_{dd_{NaOH}}=\dfrac{0.24}{0.5}=0.48\left(l\right)\)

\(FeCl_3+3NaOH\rightarrow Fe\left(OH\right)_3+3NaCl\) (1)

\(2Fe\left(OH\right)_3\rightarrow Fe_2O_3+3H_2O\) (2)

\(n_{FeCl_3}=0,2.0,4=0,08\left(mol\right)\)

Bảo toàn nguyên tố Fe : \(n_{FeCl_3}=2n_{Fe_2O_3}=0,08\left(mol\right)\)

=> \(n_{Fe_2O_3}=0,04\left(mol\right)\)

=> \(m_{Fe_2O_3}=0,04.160=6,4\left(g\right)\)

Theo PT (1) : \(n_{NaOH}=3n_{FeCl_3}=0,08.3=0,24\left(mol\right)\)

=> \(V_{NaOH}=\dfrac{0,24}{0,5}=0,48\left(l\right)\)

\(n_{FeCl_3}=C_M.V=0,4.0,2=0,08\left(mol\right)\)

PT: FeCl₃ + 3NaOH \(\rightarrow\) 3NaCl + Fe(OH)₃ \(\downarrow\)

       0,08 -> 0,24                     ->  0,08          (mol)

      2Fe(OH)₃ \(\underrightarrow{t^o}\) Fe₂O₃ + 3H₂O

        0,08       ->    0,04                                  (mol)

m_cr=m_Fe2O3=n.M=0,04.160=6,4(g)

\(V_{NaOH}=\dfrac{n}{C_M}=\dfrac{0,24}{0,5}=0,48\left(l\right)\)

\(n_{CuCl_2}=0,25.0,1=0,025(mol)\\ CuCl_2+2NaOH\to Cu(OH)_2\downarrow+2NaCl\\ \Rightarrow n_{Cu(OH)_2}=0,025(mol);n_{NaOH}=0,05(mol)\\ a,m_{Cu(OH)_2}=0,025.98=2,45(g)\\ b,C_{M_{NaOH}}=\dfrac{0,05}{0,2}=0,025M\\ 2NaCl+H_2SO_4\to Na_2SO_4+2HCl\\ \Rightarrow n_{H_2SO_4}=0,025(mol)\\ \Rightarrow m_{dd_{H_2SO_4}}=\dfrac{0,025.98}{36,5\%}\approx 6,712(g)\)