SO3 + H2O -> H2SO4

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

n SO3=0,2 mol

=>C%=\(\dfrac{0,2.98}{144+0,2.80}100\)=12,25%

Vdd=\(\dfrac{144+0,2.80}{1,25}\)=128ml

=>CMH2SO4=\(\dfrac{0,2}{0,128}\)=1,5625M

\(n_{HCl}=C_M.V=1,5.0,2=0,3\left(mol\right)\)

PTHH :

\(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)

  0,1       0,3           0,1

\(C_{M_{AlCl_3}}=\dfrac{n}{V}=\dfrac{0,1}{0,2}=0,5\left(M\right)\)

SO3 + H2O => H2SO4

nSO3 = m/M = 8/80 = 0.1 (mol)

Theo phương trình

==> nH2SO4 = 0.1 (mol)

250 ml dd = 0.25 (l) dd

C_{M ddH2SO4} = n/V = 0.1/0.25 = 0.4M

\(n_{HCl} = 0,6.2 = 1,2(mol)\\ \Rightarrow V_{dd\ HCl\ 0,75M} = \dfrac{1,2}{0,75} = 1,6(lít) = 1600(ml)\\ \Rightarrow V_{nước} = 1600 -600 = 1000(ml)\)

Giả sử hòa tan 1 mol R₂O_n

PTHH: R₂O_n + nH₂SO₄ --> R₂(SO₄)_n + nH₂O

                 1------>n----------->1-------->n

=> m_H2SO4 = 98n (g)

=> \(m_{dd.H_2SO_4}=\dfrac{98n.100}{10}=980n\left(g\right)\)

\(m_{R_2\left(SO_4\right)_n}=2.M_R+96n\left(g\right)\)

m_{dd sau pư} = m_R2On + m_{dd H2SO4}

= 2.M_R + 16n + 980n = 2.M_R + 996n (g)

\(C\%_{muối}=\dfrac{2.M_R+96n}{2.M_R+996n}.100\%=12,9\%\)

=> \(M_R=\dfrac{16242}{871}n\left(g/mol\right)\)

Chỉ có n = 3 thỏa mãn => M_R = 56 (g/mol)

=> R là Fe

CTHH của oxit là Fe₂O₃

Giả sử hòa tan 1 mol R₂O_n

PTHH: R₂O_n + nH₂SO₄ --> R₂(SO₄)_n + nH₂O

                 1------>n----------->1-------->n

=> m_H2SO4 = 98n (g)

=> \(m_{dd.H_2SO_4}=\dfrac{98n.100}{10}=980n\left(g\right)\)

\(m_{R_2\left(SO_4\right)_n}=2.M_R+96n\left(g\right)\)

m_{dd sau pư} = m_R2On + m_{dd H2SO4}

= 2.M_R + 16n + 980n = 2.M_R + 996n (g)

\(C\%_{muối}=\dfrac{2.M_R+96n}{2.M_R+996n}.100\%=12,9\%\)

=> \(M_R=\dfrac{16242}{871}n\left(g/mol\right)\)

Chỉ có n = 3 thỏa mãn => M_R = 56 (g/mol)

=> R là Fe

CTHH của oxit là Fe₂O₃

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

PT: \(Fe+2HCl\rightarrow FeCl_2+H_2\)

a, \(n_{H_2}=n_{Fe}=0,2\left(mol\right)\Rightarrow V_{H_2}=0,2.22,4=4,48\left(l\right)\)

b, \(n_{HCl}=2n_{Fe}=0,4\left(mol\right)\Rightarrow C_{M_{HCl}}=\dfrac{0,4}{0,15}=\dfrac{8}{3}\left(M\right)\)

c, \(n_{FeCl_2}=n_{Fe}=0,2\left(mol\right)\Rightarrow C_{M_{FeCl_2}}=\dfrac{0,2}{0,15}=\dfrac{4}{3}\left(M\right)\)

Sửa 5,78 thành 5,88%

Gọi kim loại là R $\Rightarrow$ Oxit là RO

Gỉa sử nRO=1 mol

$RO+H_{2}S{O}_4\to RS{O}_4+H_{2}O$

Ta có: $n_{RO}=n_{H2SO4}=n_{RSO4}=1\left(mol\right)$

$\Rightarrow m_{H2SO4}=\frac{1}{98}=98\left(g\right)$

$m_{d{d}_{H2SO4}}=\frac{98}{4,9\%}=2000\left(g\right)$

BTKL: m dung dịch sau phản ứng=mRO + m dd H2SO4

$=1\left(R+15\right)+200=R+2016($

\(n_{FeO}=\dfrac{10.8}{72}=0.15\left(mol\right)\)

\(FeO+2HCl\rightarrow FeCl_2+H_2O\)

\(0.15.......0.3.............0.15\)

\(m_{HCl}=0.3\cdot36.5=10.95\left(g\right)\)

\(C\%HCl=\dfrac{10.95}{100}\cdot100\%=10.95\%\)

\(m_{dd}=10.8+100=110.8\left(g\right)\)

\(m_{FeCl_2}=0.15\cdot127=19.05\left(g\right)\)

\(C\%FeCl_2=\dfrac{19.05}{110.8}\cdot100\%=17.19\%\)