\(m_{dd.BaCl_2}=400.1,003=401,2\left(g\right)\)

=> \(n_{BaCl_2}=\dfrac{401,2.5,2\%}{208}=0,1003\left(mol\right)\)

\(m_{dd.H_2SO_4}=100.1,14=114\left(g\right)\)

=> \(n_{H_2SO_4}=\dfrac{114.20\%}{98}=\dfrac{57}{245}\left(mol\right)\)

PTHH: BaCl₂ + H₂SO₄ --> BaSO₄ + 2HCl

Xét tỉ lệ: \(\dfrac{0,1003}{1}< \dfrac{\dfrac{57}{245}}{1}\) => BaCl₂ hết, H₂SO₄ dư

PTHH: BaCl₂ + H₂SO₄ --> BaSO₄ + 2HCl

          0,1003->0,1003-->0,1003-->0,2006

m_{dd sau pư} = 401,2 + 114 - 0,1003.233 = 491,8301 (g)

\(\left\{{}\begin{matrix}C\%_{H_2SO_4\left(dư\right)}=\dfrac{98\left(\dfrac{57}{245}-0,1003\right)}{491,8301}.100\%=2,637\%\\C\%_{HCl}=\dfrac{0,2006.36,5}{491,8301}.100\%=1,489\%\end{matrix}\right.\)

mddBaCl2 = 1,003 . 400 = 401,2 (g) mBaCl2 = 401,2 . 5,2% = 20,8624 (g)

nBaCl2 = 20,8624/208 = 0,1003 (mol)

mddH2SO4 = 1,14.100 = 114 (g) mH2SO4 = 114 . 20% = 22,8 (g)

nH2SO4 = 22,8/98 (mol)

PTHH: BaCl2 + H2SO4 -> BaSO4 + 2HCl

Bđ: 0,1003 22,8/98

Pư: 0,1003 -> 0,1003 -> 0,1003 -> 0,2006 (mol)

Sau: 0 0,132 0,1003 0,2006 (mol)

Dung dịch sau phản ứng chứa: 

mH2SO4 dư = 22,8 - 0,1003.98 = 12,9706 (g)

mHCl = 0,2006.36,5 = 7,3219 (g)

Khối lượng dd sau pư: mdd sau pư = mddBaCl2 + mddH2SO4 - mBaSO4

                                                        = 401,2 + 114 - 0,1003.233 = 491,8301 (g)

Nồng độ phần trăm: 

C% H2SO4 = (12,9706/491,8301).100% ≈ 2,64%

C% HCl = (7,3219/491,8301).100% ≈ 1,49%

\(n_{H_2SO_4}=\dfrac{100.1,14.20\%}{98}=0,233\left(mol\right)\)

\(n_{BaCl_2}=\dfrac{5,2\%.400}{108}=0,1\left(mol\right)\)

\(H_2SO_4+BaCl_2\rightarrow BaSO_4+2HCl\)

0,233..........0,1

Lập tỉ lệ : \(\dfrac{0,233}{1}>\dfrac{0,1}{1}\) => H2SO4 dư

\(m_{BaSO_4}=0,1.233=23,3\left(g\right)\)

Đáp án C

\(n_{BaCl_2}=\frac{400.5,2\%}{208}=0,1\left(mol\right);n_{H_2SO_4}=\frac{100.1,14.19,6\%}{98}=0,228\left(mol\right)\)

PTHH: \(BaCl_2+H_2SO_4\rightarrow BaSO_4+2HCl\)

Theo đề: 0,1.........0,228.....................................(mol)

Lập tỉ lệ: \(\frac{0,1}{1}< \frac{0,228}{1}\)=> Sau phản ứng H2SO4 dư

Theo PT: \(n_{BaSO_4}=n_{BaCl_2}=0,1\left(mol\right)\)

\(\Rightarrow m_{BaSO_4}=0,1.233=23,3\left(g\right)\)

dd sau khi lọc bỏ kết tủa: H2SO4 dư, HCl

\(m_{ddsaup.ứ}=400+114-23,3=490,7\left(g\right)\)

\(\Rightarrow C\%_{H_2SO_4\left(dư\right)}=\frac{\left(0,228-0,1\right).98}{490,7}.100=2,56\%\)

\(C\%_{HCl}=\frac{0,1.2.36,5}{490,7}.100=1,49\%\)

m_ddH2SO4 = 100 . 1,137 = 113,7

n_H2SO4 = 113,7 . 20%/98 = 0,232 mol

n_BaCl2 = 400 . 5,29%/208 = 0,1 mol

                 H₂SO₄ + BaCl₂ —> BaSO₄ + 2HCI

Bđ:            0,232      0,1

Pứ:            0,1        0, 1         0,1       0,2

Sau pứ:      0,132         0

m_BaSO4 = 0,1.233 = 23,3 gam

Khối lượng dung dịch sau khi lọc bỏ kết tủa:

m_ddB = m_ddH2SO4 + m_ddBaCl2 - m_BaSO4 = 490,4

C%HCI = 0,2.36,5/490,4 = 1,49%

C%_H2SO4 dư = 0,132.98/490,4 = 2,64%

Bài 27 :

Theo đề bài ta có :

mddH2O4 = D.V = 1,137 .100 = 113,7 g

=> nH2SO4 = \(\dfrac{113,7.20}{100.98}\approx0,232\left(mol\right)\)

nBaCl2 = \(\dfrac{400.5,2}{100.208}=0,1\left(mol\right)\)

PTHH :

\(BaCl2+H2SO4\rightarrow B\text{aS}o4\downarrow+2HCl\)

0,1mol.......0,1mol.........0,1mol........0,2mol

Ta có tỉ lệ : \(nBaCl2=\dfrac{0,1}{1}mol< nH2SO4=\dfrac{0,232}{1}mol\)

=> số mol của H2SO4 dư ( tính theo số mol của BaCl2 )

a) Kết tủa A tu được là BaSO4

=> mkt = mBaSO4 = 0,1 .233 = 23,3 g

b) Dung dịch B thu được bao gồm dung dịch H2SO4 dư và dung dịch HCl

mdd(sau-p/ư) = 0,1.208 + 113,7 - 23,3 = 111,2 g

=> \(C\%_{\text{dd}HCl}=\dfrac{0,2.36,5}{111,2}.100\%\approx6,565\%\)

C% ddH2SO4 dư = \(\dfrac{\left(0,232-0,1\right).98}{111,2}.100\%\approx11,633\%\)

Vậy.....

\(a)n_{BaCl_2}=\dfrac{240}{1,12}:1000\cdot1=\dfrac{3}{14}mol\\ n_{H_2SO_4}=\dfrac{122.20}{100}:98=\dfrac{61}{245}mol\\ BaCl_2+H_2SO_4\rightarrow BaSO_4+2HCl\\ \Rightarrow\dfrac{3:14}{1}< \dfrac{61:245}{1}\Rightarrow H_2SO_4.dư\\ n_{BaSO_4}=n_{BaCl_2}=n_{H_2SO_4}=\dfrac{3}{14}mol\\ m_{kt}=m_{BaSO_4}=\dfrac{3}{14}\cdot233=50g\\ c)C_{\%H_2SO_4\left(dư\right)}=\dfrac{\left(61:245-3:14\right)98}{240+122-50}\cdot100=1,2\%\)

a) 2AgNO3+CaCl2---->2AgCl+Ca(NO3)2

n AgNO3=1,7/170=0,01(mol)

n CaCl2=2,22/111=0,02(mol)

----> CaCl2 dư

Theo pthh

n AgCl=n AgNO3=0,01(mol)

m AgCl=0,01.143,5=14,35(g)

V dd sau pư=70+30=`100ml=0,1(l)

n CaCl2 dư=0,02-0,005=0,015(mol)

CM CaCl2=0,015/0,1=0,15(M)

Theo pthh

n Ca(NO3)2=1/2 n AgCl=0,005(mol)

CM Ca(NO3)2=0,005/0,1=0,05(M)

Bài 2

BaCl2+H2SO4--->BaSO4+2HCl

a) n BaCl2=400.5,2/100=20,8(g)

n BaCl2=20,8/208=0,1(mol)

m H2SO4=100.1,14.20/100=22,8(g)

n H2SO4=22,8/98=0,232(mol)

---->H2SO4 dư

Theo pthh

n BaSO4=n BaCl2=0,1(mol)

m BaSO4=0,1.233=23,3(g)

b) m dd sau pư=400+114-23,3

=490,7(g)

Theo pthh

n HCl=2n BaCl2=0,2(mol)

C%HCl=\(\frac{0,2.36,5}{490,7}.100\%=1,88\%\)

n H2SO4 dư=0,232-0,1=0,132(mol)

C% H2SO4=\(\frac{0,132.98}{490,7}.100\%=2,64\%\)

B1:

\(n_{AgNO3}=0,01\left(mol\right);n_{CaCl2}=0,2\left(mol\right)\)

PTHH:\(2AgNO3+CaCl2\rightarrow2AgCl2\downarrow+Ca\left(NO3\right)2\)

Trước :0,01................0,02..........................................................(mol)

Pứng:\(0,01\rightarrow0,005\rightarrow0,01\rightarrow0,005\)

Dư: 0............................0,015......................................................(mol)

\(m\downarrow_{AgCL}=0,01.143,5=1,435\left(g\right)\)

Trong dd sau phản ứng chứa: \(\left\{{}\begin{matrix}Ca\left(NO3\right)2:0,005\left(mol\right)\\CaCl2:0,015\left(mol\right)\end{matrix}\right.\)

\(C_{M_{Ca\left(NO3\right)2}}=\frac{0,005}{0,1}=0,05M\)

\(C_{M_{CaCl2}}=\frac{0,015}{0,1}=0,15M\)

Bài 2:\(n_{BaCl2}=\frac{400.5,2}{100.208}=0,1\left(mol\right)\)

\(D=\frac{m_{dd}}{v_{dd}};C\%=\frac{m_{ct}}{m_{dd}}.100\Rightarrow m_{H2SO4}=\frac{D.v.d^2.C\%}{100}=22,8g\)

\(\Rightarrow n_{H2SO4}=0,23\left(mol\right)\)

\(BaCl2+HSO4\rightarrow BaSO4\downarrow+2HCl\)

0,1..............0,1............0,1.................0,2.....(mol)

\(a,m_{\downarrow}=0,1.223=23,3\left(g\right)\)

\(b,m_{dd_{saupu}}=m_{BaCl2}+m_{dd_{H2SO4}}-m_{\downarrow}_{BaSO4}\)

\(=400+1,14.100-23,3=490,7\)

\(\Rightarrow C\%_{HCl}=\frac{0,2.36,5}{490,7}.100\%=1,48\%\)

\(\%H2SO4_{du}=\frac{\left(0,23-0,1\right).98}{490,7}.100=2,59\%\)