a)nMgO=0,15(mol)

Ta có PTHH:

MgO+H2SO4->MgSO4+H2O

0,15......0,15...........0,15..................(mol)

Theo PTHH:mH2SO4=0,15.98=14,7g

b)Ta có:mddH2SO4=1,2.50=60(g)

=>Nồng độ % dd H2SO4là:

C%ddH2SO4=\(\dfrac{14,7}{60}100\)=24,5%

c)Theo PTHH:mMgSO4=0,15.120=18(g)

Khối lượng dd sau pư là:

mddsau=6+60=66(g)

Vậy nồng độ % dd sau pư là:

C%ddsau=\(\dfrac{18}{66}.100\)=27,27%

\(n_{FeO}=a\left(mol\right),n_{CuO}=b\left(mol\right)\)

\(m_{hh}=72a+80b=19.2\left(g\right)\left(1\right)\)

\(FeO+H_2SO_4\rightarrow FeSO_4+H_2O\)

\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\)

\(n_{H_2SO_4}=a+b=0.25\left(mol\right)\left(2\right)\)

\(\left(1\right),\left(2\right):a=0.1,b=0.15\)

\(m_{FeO}=0.1\cdot72=7.2\left(g\right)\)

\(m_{CuO}=12\left(g\right)\)

\(C_{M_{FeSO_4}}=\dfrac{0.1}{0.25}=0.4\left(M\right)\)

\(C_{M_{CuSO_4}}=\dfrac{0.15}{0.25}=0.6\left(M\right)\)

a. PTHH: Zn + H₂SO₄ ---> ZnSO₄ + H₂↑

b. Ta có: \(C_{M_{H_2SO_4}}=\dfrac{n_{H_2SO_4}}{200:1000}=1,5M\)

=> \(n_{H_2SO_4}=0,3\left(mol\right)\)

Ta lại có: \(n_{Zn}=\dfrac{16,25}{65}=0,25\left(mol\right)\)

Ta thấy: \(\dfrac{0,3}{1}>\dfrac{0,25}{1}\)

Vậy H₂SO₄ dư.

Theo PT: \(n_{H_2}=n_{Zn}=0,25\left(mol\right)\)

=> \(V_{H_2}=0,25.22,4=5,6\left(lít\right)\)

c. Theo PT: \(n_{ZnSO_4}=n_{Zn}=0,25\left(mol\right)\)

=> \(m_{ZnSO_4}=0,25.161=40,25\left(g\right)\)

d. Ta có: \(V_{dd_{ZnSO_4}}=0,2\left(lít\right)\)

=> \(C_{M_{ZnSO_4}}=\dfrac{0,25}{0,2}=1,25M\)

a)

$n_{Al} = 0,3(mol)$

$2Al + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2$

Theo PTHH : 

$n_{H_2SO_4} = \dfrac{3}{2}n_{Al} = 0,45(mol)$
$m_{dd\ H_2SO_4} = \dfrac{0,45.98}{12,25\%} = 360(gam)$

b)

$n_{H_2} = n_{H_2SO_4} = 0,45(mol)$
$V_{H_2} = 0,45.22,4 = 10,08(lít)$

c)

$n_{Al_2(SO_4)_3} = 0,15(mol)$
$m_{dd\ sau\ pư} = 8,1 + 360 - 0,45.2 = 367,2(gam)$
$C\%_{Al_2(SO_4)_3} = \dfrac{0,15.342}{367,2}.100\% = 14\%$

\(n_{CuO}=\dfrac{4}{80}=0,05\left(mol\right)\\a, CuO+H_2SO_4\rightarrow CuSO_4+H_2O\\ n_{CuSO_4}=n_{H_2SO_4}=n_{CuO}=0,05\left(MOL\right)\\ b,m_{CuSO_4}=0,05.160=8\left(g\right)\\ c,V_{ddH_2SO_4}=\dfrac{0,05}{0,5}=0,1\left(l\right)\\ d,V_{ddCuSO_4}=V_{ddH_2SO_4}=0,1\left(l\right)\\ C_{MddCuSO_4}=\dfrac{0,05}{0,1}=0,5\left(M\right)\)

 \(Fe+2CH_3COOH\rightarrow\left(CH_3COO\right)_2Fe+H_2\)

\(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)\)

Theo PT: \(n_{\left(CH_3COO\right)_2Fe}=n_{Fe}=0,2\left(mol\right)\Rightarrow m_{\left(CH_3COO\right)_2Fe}=0,2.174=34,8\left(g\right)\)

Ta có: \(n_{H_2}=n_{Fe}=0,2\left(mol\right)\)

m _{dd sau pư} = 11,2 + 200 - 0,2.2 = 210,8 (g)

\(\Rightarrow C\%_{\left(CH_3COO\right)_2Fe}=\dfrac{34,8}{210,8}.100\%\approx16,51\%\)

a, \(H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O\)

b, \(n_{H_2SO_4}=0,2.1=0,2\left(mol\right)\)

Theo PT: \(n_{NaOH}=2n_{H_2SO_4}=0,4\left(mol\right)\)

\(\Rightarrow m_{ddNaOH}=\dfrac{0,4.40}{20\%}=80\left(g\right)\)

c, Theo PT: \(n_{Na_2SO_4}=n_{H_2SO_4}=0,2\left(mol\right)\)

\(\Rightarrow C\%_{Na_2SO_4}=\dfrac{0,2.142}{100}.100\%=28,4\%\)

a, PT: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)

b, Ta có: \(n_{H_2}=0,15\left(mol\right)\)

Theo PT: \(n_{Al}=\dfrac{2}{3}n_{H_2}=0,1\left(mol\right)\)

\(\Rightarrow m_{Al}=0,1.27=2,7\left(g\right)\)

\(\Rightarrow m_{Al_2O_3}=7,8-2,7=5,1\left(g\right)\)

c, Có: \(n_{Al_2O_3}=\dfrac{5,1}{102}=0,05\left(mol\right)\)

Theo PT: \(n_{HCl}=3n_{Al}+6n_{Al_2O_3}=0,6\left(mol\right)\)

\(n_{AlCl_3}=n_{Al}+2n_{Al_2O_3}=0,2\left(mol\right)\)

\(\Rightarrow m_{HCl}=0,6.36,5=21,9\left(g\right)\Rightarrow m_{ddHCl}=\dfrac{21,9}{10\%}=219\left(g\right)\)

⇒ m _{dd sau pư} = 7,8 + 219 - 0,15.2 = 226,5 (g)

\(\Rightarrow C\%_{AlCl_3}=\dfrac{0,2.133,5}{226,5}.100\%\approx11,79\%\)

Bạn tham khảo nhé!