a)PTHH: \(Ba\left(OH\right)+Na_2CO_3\rightarrow2NaOH+BaCO_3\downarrow\)

             \(BaCO_3\underrightarrow{t^o}BaO+CO_2\uparrow\)

Ta có: \(n_{Ba\left(OH\right)_2}=0,4\cdot0,2=0,08\left(mol\right)\)

\(\Rightarrow n_{NaOH}=0,16mol\) \(\Rightarrow C_{M_{NaOH}}=\dfrac{0,16}{0,4}=0,4\left(M\right)\) (Coi V_dd thay đổi không đáng kể)

b) Theo PTHH: \(n_{BaCO_3}=n_{Ba\left(OH\right)_2}=n_{BaO}=0,08mol\) \(\Rightarrow m_{BaO}=0,08\cdot153=12,24\left(g\right)\)

a. Ba(OH)₂ +Na₂CO₃ ➝ BaCO₃ + 2NaOH

BaCO₃ ➝ BaO + CO₂

nBa(OH)₂ = 0,08 mol

=> nNaOH = 2nBa(OH)₂ = 0,16 mol

=> C_M = 0,4 M

b) Bảo toàn Ba: nBaO = nBa(OH)₂ = 0,08 mol

=> m = 12,24 g

\(n_{CuSO_4}=\dfrac{200.16\%}{160}=0,2\left(mol\right)\)

PTHH :

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

0,2              0,4                  0,2               0,2 

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

\(m_{ddNaOH}=\dfrac{16.100}{10}=160\left(g\right)\)

\(c,m_{Na_2SO_4}=0,2.142=28,4\left(g\right)\)

\(m_{ddNa_2SO_4}=200+160-\left(0,2.98\right)=340,4\left(g\right)\)

\(C\%_{Na_2SO_4}=\dfrac{28,4}{240,4}.100\%\approx8,34\%\)

\(d,PTHH:\)

\(Cu\left(OH\right)_2\underrightarrow{t^o}CuO+H_2O\)

0,2               0,2 

\(m_{CuO}=0,2.80=16\left(g\right)\)

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

b, \(m_{CuSO_4}=200.16\%=32\left(g\right)\Rightarrow n_{CuSO_4}=\dfrac{32}{160}=0,2\left(mol\right)\)

\(n_{NaOH}=2n_{CuSO_4}=0,4\left(mol\right)\Rightarrow m_{ddNaOH}=\dfrac{0,4.40}{10\%}=160\left(g\right)\)

c, \(n_{Cu\left(OH\right)_2}=n_{Na_2SO_4}=n_{CuSO_4}=0,2\left(mol\right)\)

\(\Rightarrow C\%_{Na_2SO_4}=\dfrac{0,2.142}{200+160-0,2.98}.100\%\approx8,34\%\)

d, \(Cu\left(OH\right)_2\underrightarrow{t^o}CuO+H_2O\)

\(n_{CuO}=n_{Cu\left(OH\right)_2}=0,2\left(mol\right)\Rightarrow m_{CuO}=0,2.80=16\left(g\right)\)

a.CuCl2 + 2NaOH -> Cu(OH)2 + 2NaCl

     0.15        0.3            0.15            0.3

Cu(OH)2 -> CuO + H2O

  0.15            0.15

nNaOH = 0.3 mol

\(CM_{CuCl2}=\dfrac{0.15}{2}=0.075M\)

b.Vdd sau phản ứng = 0.2 + 0.15 = 0.35l

\(CM_{NaCl}=\dfrac{0.3}{0.35}=0.86M\)

c.mCuO = \(0.15\times80=12g\)

a) \(n_{NaOH}=\dfrac{20}{40}=0,5\left(mol\right)\)

PTHH: CuCl₂ + 2NaOH --> Cu(OH)₂ + 2NaCl

Xét tỉ lệ: \(\dfrac{0,2}{1}< \dfrac{0,5}{2}\) => CuCl₂ hết, NaOH dư

PTHH: CuCl₂ + 2NaOH --> Cu(OH)₂ + 2NaCl

              0,2------>0,4-------->0,2------->0,4

            Cu(OH)₂ --t^o--> CuO + H₂O

               0,2-------------->0,2

=> m_CuO = 0,2.80 = 16(g)

b)

\(\left\{{}\begin{matrix}m_{NaOH\left(dư\right)}=20-0,4.40=4\left(g\right)\\m_{NaCl}=0,4.58,5=23,4\left(g\right)\end{matrix}\right.\)

\(n_{MgCl_2}=0,15.0,2=0,03(mol)\\ PTHH:MgCl_2+2NaOH\to Mg(OH)_2\downarrow +2NaCl\\ a,n_{Mg(OH)_2}=n_{MgCl_2}=0,03(mol)\\ \Rightarrow m_{\downarrow}=m_{Mg(OH)_2}=0,03.58=1,74(g)\\ b,n_{NaOH}=2n_{MgCl_2}=0,06(mol)\\ \Rightarrow C_{M_{NaOH}}=\dfrac{0,06}{0,3}=0,2M\\ c,PTHH:Mg(OH)_2\xrightarrow{t^o}MgO+H_2O\\ \Rightarrow n_{MgO}=n_{Mg(OH)_2}=0,03(mol)\\ \Rightarrow m_{A}=m_{MgO}=0,03.40=1,2(g)\)