n Ba(OH)2 = 2.0,2=0,4 mol

  \(Ba\left(OH\right)_2+SO_2->BaSO_3+H_2O\)

0,4 ................0,4...........0,4

m BaSO3 = 0,4. ( 138+32+16.3)=87,2 g 

v SO2 = 0,4.22,4=8,96 lít

a) nBa(OH)2= (200.17,1%)/171=0,2(mol)

nCuSO4=(500.8%)/160=0,25(mol)

PTHH: CuSO4 + Ba(OH)2 -> BaSO4 + Cu(OH)2

+ Kt A có Cu(OH)2 và BaSO4.

+ dd B có dd CuSO4 dư (Vì 0,25/1 > 0,2/1 =>dd CuSO4 dư)

a) mA=mCu(OH)2+ mBaSO4=0,2.98+0,2.233= 66,2(g)

b) mddB= mddBa(OH)2+ mddCuSO4 - mktA= 200+500- 66,2= 633,8(g)

mCuSO4(dư)=(0,25-0,2).160=8(g)

=>C%ddCuSO4(dư)=(8/633,8).100=1,262%

Theo giả thiết ta có : nCO2 = 6,72/22,4 = 0,3 (mol)

a) PTHH :

0,3mol......0,3mol................0,3mol.........0,3mol

b) nồng độ mol của dd Ba(OH)2 đã dùng là :

Câu 15: 

Bảo toàn nguyên tố: \(n_{CO_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)=n_{BaCO_3}=n_{Ba\left(OH\right)_2}\)

\(\Rightarrow\left\{{}\begin{matrix}m_{BaCO_3}=0,3\cdot197=59,1\left(g\right)\\C_{M_{Ba\left(OH\right)_2}}=\dfrac{0,3}{0,6}=0,5\left(M\right)\end{matrix}\right.\)

Bài 3:

a) \(CaO+SO_2\rightarrow CaSO_3\)

b) \(CaO+HNO_3\rightarrow Ca\left(NO_3\right)_2+H_2O\)

c) \(CaO+H_2SO_4\rightarrow CaSO_4+H_2O\)

Bài 2:

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

                 a_____2a_______a_______a     (mol)

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

                    b_____6b_______2b_______3a     (mol)

Ta lập HPT: \(\left\{{}\begin{matrix}80a+160b=20\\2a+6b=0,2\cdot3,5=0,7\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=0,05\\b=0,1\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}m_{CuO}=0,05\cdot80=4\left(g\right)\\m_{Fe_2O_3}=16\left(g\right)\end{matrix}\right.\) 

Bài 2:

PTHH: \(Ba\left(OH\right)_2+CO_2\rightarrow BaCO_3\downarrow+H_2O\)

Ta có: \(n_{CO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)=n_{Ba\left(OH\right)_2}\) \(\Rightarrow C_{M_{Ba\left(OH\right)_2}}=\dfrac{0,2}{0,4}=0,5\left(M\right)\)

Ta có: 

\(n_{SO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)

\(SO_2+Ba\left(OH\right)_2\rightarrow BaSO_3\downarrow+H_2O\)

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

\(m_{kt}=m_{BaSO_3}=0,2.217=43,4\left(g\right)\)

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

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

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