Đặt: \(m_{ddH_2SO_4\left(30\%\right)}=a\left(g\right)\\ \rightarrow m_{ddH_2SO_4}=a+150\left(g\right)\) (a>0)

=>\(\Sigma m_{H_2SO_4}=0,3a+15\left(g\right)\)

Vì nồng độ dung dịch H₂SO₄ sau trộn là 17%. Nên ta có phương trình:

\(\dfrac{0,3a+15}{a+150}.100=17\%\\ \Leftrightarrow a\approx80,769\left(g\right)\)

Vậy: Dung dịch H₂SO₄ ban đầu có khối lượng khoảng 80,769(g)

tham khảo:

\(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\)

a) Pt : \(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2|\)

            2             3                  1               3

           0,4         0,6                0,2            0,6

\(n_{H2}=\dfrac{0,4.3}{2}=0,6\left(mol\right)\)

\(V_{H2\left(dktc\right)}=0,6.22,4=13,44\left(l\right)\)

b) \(n_{H2SO4}=\dfrac{0,4.3}{2}=0,6\left(mol\right)\)

⇒ \(m_{H2SO4}=0,6.98=58,8\left(g\right)\)

\(C_{ddH2SO4}=\dfrac{58,8.100}{189,2}=31,08\)⁰/₀

c) \(n_{Al2\left(SO4\right)3}=\dfrac{0,6.1}{3}=0,2\left(mol\right)\)

⇒ \(m_{Al2\left(SO4\right)3}=0,2.342=68,4\left(g\right)\)

\(m_{ddspu}=10,8+189,2-\left(0,6.2\right)=198,8\left(g\right)\)

\(C_{Al2\left(SO4\right)3}=\dfrac{68,4.100}{198,8}=34,41\)⁰/₀

 Chúc bạn học tốt

\(n_{H_2SO_4}=\dfrac{150.9,8\%}{98}=0,15\left(mol\right)\\ H_2SO_4+Na_2CO_3\rightarrow Na_2SO_4+H_2O+CO_2\\ n_{Na_2CO_3}=n_{H_2SO_4}=0,15\left(mol\right)\\ \Rightarrow m_{ddNa_2CO_3}=\dfrac{0,15.106}{10,6\%}=150\left(g\right)\\ n_{CO_2}=n_{H_2SO_4}=0,15\left(mol\right)\\ m_{ddsaupu}=150+150-0,15.44=293,4\left(g\right)\\ n_{Na_2SO_4}=n_{H_2SO_4}=0,15\left(mol\right)\\ C\%_{Na_2SO_4}=\dfrac{0,15.142}{293,4}.100=7,26\%\)

\(m_{H_2SO_4}=150.9,8\%=14,7\left(g\right)\\ n_{H_2SO_4}=\dfrac{14,7}{98}=0,3\left(mol\right)\\ PTHH:H_2SO_4+Na_2CO_3\rightarrow Na_2SO_4+CO_2\uparrow+H_2O\\ Mol:0,3\rightarrow0,3\rightarrow0,3\rightarrow0,3\)

\(m_{Na_2CO_3}=0,3.106=31,8\left(g\right)\\ m_{ddNa_2CO_3}=\dfrac{31,8}{10,6\%}=300\left(g\right)\\ m_{Na_2SO_4}=0,3.142=42,6\left(g\right)\\ m_{CO_2}=0,3.44=13,2\left(g\right)\\ m_{dd}=150+300-13,2=436,8\left(g\right)\\ C\%_{Na_2SO_4}=\dfrac{42,6}{436,8}=9,75\%\)

mH2SO4 =mdd H2SO4.C% : 100% = 400.9,8% :100% = 39,2 (g)

=> nH2SO4 = mH2SO4 : MH2SO4 = 39,2: 98 = 0,4 (mol)

PTHH: H2SO4 + Na2CO3 ---> Na2SO4 + CO2 + H2O

0,4 ---->0,4 -----------> 0,4 -------> 0,4 (mol)

a) Theo PTHH: nNa2CO3 = nH2SO4 = 0,4 (mol)

=> mNa2CO3 = nNa2CO3. MNa2CO3 = 0,4.106 = 42,4 (g)

=> mdd Na2CO3 = mNa2CO3. 100% : C% = 42,4.100% : 10% = 424 (g)

b) Theo PTHH: nCO2 = nH2SO4 = 0,4 (mol)

=> VCO2(đktc) = 0,4.22,4 = 8,96 (lít)

c) Theo PTHH: nNa2SO4 = nH2SO4 = 0,4 (mol)

=> mNa2SO4 = nNa2SO4. MNa2SO4 = 0,4.142 = 56,8 (g)

mdd A = mdd H2SO4 + mdd Na2CO3 = 400 + 424 = 824 (g)

dd A chứa Na2SO4

=> C% Na2SO4 = (mNa2SO4 : mddA).100% = (56,8 : 824).100% = 6,89%

\(a.n_{Zn}=\dfrac{32,5}{65}=0,5\left(mol\right)\\ PTHH:Zn+H_2SO_4\rightarrow ZnSO_4+H_2\\ 0,5..........0,5...........0,5........0,5\left(mol\right)\\ b.V_{H_2\left(đktc\right)}=0,5.22,4=11,2\left(l\right)\\ c.m_{ddH_2SO_4}=\dfrac{0,5.98.100}{9}=\dfrac{4900}{9}\left(g\right)\\ d.C\%_{ddZnSO_4}=\dfrac{0,5.161}{\dfrac{4900}{9}}.100\approx14,786\%\)

\(Fe+H_2SO_4\rightarrow FeSO_4+H_2\\ n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\\Tacó: n_{Fe}=n_{H_2SO_4}=n_{FeSO_4}=n_{H_2}=0,2\left(mol\right)\\ \Rightarrow m_{FeSO_4}=0,2.152=30,4\left(g\right)\\ \Rightarrow V_{H_2}=0,2.22,4=4,48\left(l\right)\\ \Rightarrow C\%_{H_@SO_4}=\dfrac{0,2.98}{200}.100=9,8\%\)

a)b)c)d) mBaCl2=150.16,64%=24,96g

=>nBaCl2=0,12 mol

mH2SO4=100.14,7%=14,7g=>nH2SO4=0,15mol

     BaCl2       + H2SO4 =>BaSO4    +2HCl

Bđ: 0,12 mol;    0,15 mol

Pứ: 0,12 mol=>0,12 mol=>0,12 mol=>0,24 mol

Dư:                   0,03 mol

Dd ban đầu chứa BaCl2 0,12 mol và H2SO4 0,15 mol

Dd A sau phản ứng chứa HCl 0,24 mol và H2SO4 dư 0,03 mol

mHCl=0,24.36,5=8,76g

mH2SO4=0,03.98=2,94g

Kết tủa B là BaSO4 0,12 mol=>mBaSO4=0,12.233=27,96g

mddA=mddBaCl2+mddH2SO4-mBaSO4

=150+100-27,96=222,04g

C%dd HCl=8,76/222,04.100%=3,945%

C% dd H2SO4=2,94/222,04.100%=1,324%

e) HCl     +NaOH =>NaCl +H2O

0,24 mol=>0,24 mol

H2SO4 +2NaOH =>Na2SO4 + 2H2O

0,03 mol=>0,06 mol

TÔNG nNaOH=0,3 mol

=>V dd NaOH=0,3/2=0,15 lit

Ta có: \(C_{\%_{Ba\left(OH\right)_2}}=\dfrac{m_{Ba\left(OH\right)_2}}{250}.100\%=34,2\%\)

=> \(m_{Ba\left(OH\right)_2}=85,5\left(g\right)\)

=> \(n_{Ba\left(OH\right)_2}=\dfrac{85,5}{171}=0,5\left(mol\right)\)

Ta lại có: \(C_{\%_{H_2SO_4}}=\dfrac{m_{H_2SO_4}}{150}.100\%=4,9\%\)

=> \(m_{H_2SO_4}=7,35\left(g\right)\)

=> \(n_{H_2SO_4}=\dfrac{7,35}{98}=0,075\left(mol\right)\)

a. PTHH; Ba(OH)₂ + H₂SO₄ ---> BaSO₄↓ + 2H₂O

Ta thấy: \(\dfrac{0,5}{1}>\dfrac{0,075}{1}\)

Vậy Ba(OH)₂ dư.

Theo PT: \(n_{BaSO_4}=n_{H_2SO_4}=0,075\left(mol\right)\)

=> \(m_{BaSO_4}=0,075.233=17,475\left(g\right)\)

b. Ta có: \(m_{dd_{BaSO_4}}=250+7,35=257,35\left(g\right)\)

=> \(C_{\%_{BaSO_4}}=\dfrac{17,475}{257,35}.100\%=6,79\%\)

Ko cần nhé

Chỉ hỏi bazơ thôi, ko dư nhé

a)

$Fe + H_2SO_4 \to FeSO_4 + H_2$

Theo PTHH : 

$n_{H_2} = n_{H_2SO_4} = n_{Fe} = \dfrac{0,56}{56} = 0,01(mol)$
$V_{H_2} = 0,01.22,4 = 0,224(lít)$

b) $C_{M_{H_2SO_4}} = \dfrac{0,01}{0,2} = 0,05M$