a)

$CuO + H_2SO_4 \to CuSO_4 + H_2O$

Theo PTHH : 

$n_{CuO} = n_{H_2SO_4} = \dfrac{98.40\%}{98} = 0,4(mol)$
$m = 0,4.80 = 32(gam)$

b)

$m_{dd\ sau\ pư} = 32 + 98 = 130(gam)$
$n_{CuSO_4} = n_{H_2SO_4} = 0,4(mol)$
$C\%_{CuSO_4} = \dfrac{0,4.160}{130}.100\% = 49,23\%$

a) \(m_{H_2SO_4}=98.40\%=39,2\left(g\right)\Rightarrow n_{H_2SO_4}=\dfrac{39,2}{98}=0,4\left(mol\right)\)

PTHH: CuO + H₂SO₄ → CuSO₄ + H₂O

Mol:       0,4       0,4             0,4

\(m_{CuO}=0,4.80=32\left(g\right)\)

b) m_{dd sau pứ} = 32 + 98 = 130 (g)

\(C\%_{ddCuSO_4}=\dfrac{0,4.160.100\%}{130}=49,23\%\)

\(m_{ct}=\dfrac{20.98}{100}=19,6\left(g\right)\)

\(n_{H2SO4}=\dfrac{19,6}{98}=0,2\left(mol\right)\)

Pt : \(CuO+H_2SO_4\rightarrow CuSO_4+H_2O|\)

         1             1               1             1

        0,2          0,2           0,2

a) \(n_{CuO}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)

⇒ \(m_{CuO}=0,2.80=16\left(g\right)\)

b) \(n_{CuSO4}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)

⇒ \(m_{CuSO4}=0,2.160=32\left(g\right)\)

c) \(m_{ddspu}=16+98=114\left(g\right)\)

\(C_{CuSO4}=\dfrac{32.100}{114}=28,7\)⁰/₀

 Chúc bạn học tốt

1)

a, \(n_{Al}=\dfrac{15,3}{102}=0,15\left(mol\right)\)

PTHH: Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O

Mol:     0,15         0,9        0,3      

\(m_{ddHCl}=\dfrac{0,9.36,5.100}{20}=164,25\left(g\right)\)

b, m_{dd sau pứ} = 15,3 + 164,25 = 179,55 (g)

c, \(C\%_{ddAlCl_3}=\dfrac{0,3.133,5.100\%}{179,55}=22,31\%\)

2)

a, \(m_{HCl}=54,75.20\%=10,95\left(g\right)\Rightarrow n_{HCl}=\dfrac{10,95}{36,5}=0,3\left(mol\right)\)

PTHH: Al₂O₃  + 6HCl → 2AlCl₃ + 3H₂O

Mol:      0,05        0,3          0,1

\(m_{Al_2O_3}=0,05.102=5,1\left(g\right)\)

b, m_{dd sau pứ} = 5,1 + 54,75 = 59,85 (g) 

\(C\%_{ddAlCl_3}=\dfrac{0,1.133,5.100\%}{59,85}=22,31\%\)

a,

CuO+H2SO4--->CuSO4+H2O
nCuO=32/80=0,4 mol
=> nH2SO4=nCuO=0,4 mol
=> mH2SO4=0,4*98=39,2g
=> mddH2SO4=m=39,2/20%=196g
b.

Theo định luật bảo toàn khối lượng, mCuO+mddH2SO4=mddCuSO4+mH2O (tạo ra). Khối lượng dung dịch sau phản ứng là mddCuSO4+mH2O (tạo ra) và cũng bằng mCuO+mddH2SO4=32+196=228g
=> mdd sau phản ứng = 228g
c,

nCuSO4=0,4 mol
=> mCuSO4=160*0,4=64g
=> C% CuSO4=mCuSO4/mdd sau pư=64/228*100%=28,07%

\(n_{CuO}=\dfrac{32}{80}=0,4\left(mol\right)\\ CuO+H_2SO_4\rightarrow CuSO_4+H_2O\\ 0,4...........0,4........0,4..........0,4\left(mol\right)\\ a.m=m_{ddH_2SO_4}=\dfrac{0,4.98.100}{20}=196\left(g\right)\\ b.m_{ddCuSO_4}=m_{CuO}+m_{ddH_2SO_4}=32+196=228\left(g\right)\\ C\%_{ddCuSO_4}=\dfrac{0,4.160}{228}.100\approx28,07\%\)

nAl2O3= 10,2/102= 0,1(mol)

a) PTHH: Al2O3 + 6 HCl -> 2 AlCl3 + 3 H2O

0,1_______0,6_______0,2_________0,3(mol)

mHCl=0,6.36,5= 21,9(g)

=>mddHCl= (21,9.100)/7,3=300(g)

b) mddsau= mAl2O3 + mddHCl= 10,2+300=310,2(g)

c) mAlCl3= 133,5.0,2=26,7(g)

=>C%ddAlCl3= (26,7/310,2).100=8,607%

a) Al₂O₃ + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂O

b) \(n_{Al_2O_3}=\dfrac{10,2}{102}=0,1\left(mol\right)\)

PTHH: Al₂O₃ + 3H₂SO₄ --> Al₂(SO₄)₃ + 3H₂O

                0,1---->0,3------->0,1

=> m = 0,1.342 = 34,2 (g)

c) \(C\%_{dd.H_2SO_4}=\dfrac{0,3.98}{120}.100\%=24,5\%\)

Al2O3+3H2SO4->Al2(SO4)3+3H2O

0,1------0,3------0,1-------------------0,3

n Al2O3=0,1 mol

m Al2(SO4)3=0,1.342=34,2g

C%=\(\dfrac{0,3.98}{120}100=24,5\%\)

\(a.Al_2O_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2 O\\ b.n_{Al_2O_3}=0,1\left(mol\right)\\ n_{Al_2\left(SO_4\right)_3}=n_{Al_2O_3}=0,1\left(mol\right)\\ \Rightarrow m_{Al_2\left(SO_4\right)_3}=0,1.342=34,2\left(g\right)\\ c.n_{H_2SO_4}=3n_{Al_2O_3}=0,3\left(mol\right)\\ C\%_{H_2SO_4}=\dfrac{0,3.98}{120}.100=24,5\%\)

\(n_{Fe_2O_3}=\dfrac{8}{160}=0,05\left(mol\right)\)

PTHH: Fe₂O₃ + 3H₂SO₄ --> Fe₂(SO₄)₃ + 3H₂O

______0,05------>0,15--------->0,05

=> m_H2SO4 = 0,15.98 = 14,7(g)

=> \(C\%\left(H_2SO_4\right)=\dfrac{14,7}{100}.100\%=14,7\%\)

\(C\%\left(Fe_2\left(SO_4\right)_3\right)=\dfrac{0,05.400}{8+100}.100\%=18,52\%\)

PTHH: Fe₂(SO₄)₃ + 6NaOH --> 2Fe(OH)₃\(\downarrow\) + 3Na₂SO₄

________0,05----------------------->0,1

=> mFe(OH)₃ = 0,1.107=10,7(g)

nFe2O3= 4,8/160= 0,03(mol)

nH2SO4= (300.9,8%)/98= 0,3(mol)

PTHH: Fe2O3 + 3 H2SO4 -> Fe2(SO4)3 + 3 H2O

Ta có: 0,03/1 < 0,3/3

=> H2SO4 dư, Fe2O3 hết.

- Chất tan trong dd thu được có Fe2(SO4)3 và H2SO4(dư)

nFe2(SO4)3= nFe2O3=0,03(mol)

=>mFe2(SO4)3= 400.0,03= 12(g)

nH2SO4(dư)= 0,3 - 0,03.3= 0,21(mol)

=>mH2SO4(dư)= 0,21. 98=20,58(g)

mddsau= mFe2O3+ mddH2SO4= 4,8+300=304,8(g)

=>C%ddFe2(SO4)3= (12/304,8).100=3,937%

C%ddH2SO4(dư)= (20,58/304,8).100=6,752%

a. PTHH: Fe₂O₃ + 6HCl ---> 2FeCl₃ + 3H₂O

Ta có: \(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)

Ta có: \(C\%_{HCl}=\dfrac{m_{HCl}}{146}.100\%=20\%\)

=> m_HCl = 29,2(g)

=> n_HCl = \(\dfrac{29,2}{35,5}\approx0,8\left(mol\right)\)

Ta thấy: \(\dfrac{0,1}{1}< \dfrac{0,8}{6}\)

Vậy HCl dư

Theo PT: \(n_{FeCl_3}=2.n_{Fe_2O_3}=2.0,1=0,2\left(mol\right)\)

=> \(m_{ct_{FeCl_3}}=0,2.162,5=32,5\left(g\right)\)

b. Ta có: \(m_{dd_{FeCl_3}}=16+146=162\left(g\right)\)

=> \(C\%_{FeCl_3}=\dfrac{32,5}{162}.100\%=20,06\%\)