a, SO₄  hóa trị II

b, Br hóa trị I

c, NO₃ hóa trị I

\(n_{HCl}=0,3.2=0,6\left(mol\right)\)

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

a, \(n_{Al}=\dfrac{1}{3}n_{HCl}=0,2\left(mol\right)\)

\(\Rightarrow m_{Al}=0,2.27=5,4\left(g\right)\)

b, \(n_{H_2}=\dfrac{1}{2}n_{HCl}=0,3\left(mol\right)\)

\(\Rightarrow V_{H_2}=0,3.22,4=6,72\left(l\right)\)

Câu 20: Vì khí H₂ nhẹ hơn KK (tỉ khối giữa khí H₂ với KK là 2/29<1) nên khí H₂ sẽ bay lên →Đặt ngược bình

-Khí O₂ nặng hơn KK (tỉ khối giữa khí O₂ và KK là 32/29>1) nên khí O₂ sẽ đi xuống →Đặt đứng bình

PTHH: 8Al + 30HNO₃ --> 8Al(NO₃)₃ + 3N₂O + 15H₂O

____2,4 <---------------------------------0,9

=> n_Al = 2,4 (mol)

\(QToxh:Al\rightarrow Al^{3+}+3e\\ QTkhử:2N^{+5}+8e\rightarrow N_2^{+1}\\ BTe:n_{Al}.3=n_{N_2O}.8\\ \Rightarrow n_{Al}=2,4\left(mol\right)\)

\(a)n_{H_2}=\dfrac{14,874}{24,79}=0,6mol\\2 Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

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

\(m_{Al}=0,4.27=10,8g\\ b)m_{Al_2\left(SO_4\right)_3}=0,2.342=68,4g\\ c)m_{H_2SO_4}=0,6.98=58,8g\)

tk

b , m A l ( N O 3 ) 3 = 1 , 5 ⋅ 213 = 319 , 5 ( g )

a)

\(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

0,2--->0,3------->0,1------------>0,3

$m_{dd.H_2SO_4}=\frac{0,3.98.100\%}{19,6\%}=150\left(g\right)$

b)

\(V_{H_2}=0,3.22,4=6,72\left(l\right)\)

c)

\(C\%_{Al_2\left(SO_4\right)_3}=\dfrac{0,1.342.100\%}{5,4+150-0,3.2}=22,09\%\)

Ta có: \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)

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

_____0,2_______0,3________0,1_______0,3 (mol)

a, \(m_{H_2SO_4}=0,3.98=29,4\left(g\right)\Rightarrow m_{ddH_2SO_4}=\dfrac{29,4}{19,6\%}=150\left(g\right)\)

b, \(V_{H_2}=0,3.22,4=6,72\left(l\right)\)

c, Ta có: m _{dd sau pư} = 5,4 + 150 - 0,3.2 = 154,8 (g)

\(\Rightarrow C\%_{Al_2\left(SO_4\right)_3}=\dfrac{0,1.342}{154,8}.100\%\approx22,09\%\)

\(a)n_{Al}=\dfrac{5,4}{27}=0,2mol\\ 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\\ 0,2.........0,3.................0,1........0,3\\ m_{ddH_2SO_4}=\dfrac{0,3.98}{19,6}\cdot100=150g\\ b)V_{H_2\left(đktc\right)}=0,3.22,4=6,72l\\ c)C_{\%Al_2\left(SO_4\right)_3}=\dfrac{0,1.342}{5,4+150-0,3.2}\cdot100=22,9\%\)

1) 

a) Từ trái qua phải : 

\(4FeS+7O_2\xrightarrow[]{t^o}2Fe_2O_3+4SO_2\)

\(2SO_2+O_2\xrightarrow[V_2O_5]{t^o}2SO_3\)

\(SO_3+H_2O\rightarrow H_2SO_4\)

\(Cu+2H_2SO_{4\left(đ,n\right)}\rightarrow CuSO_4+H_2O+SO_2\uparrow\)

Bạn xem lại chỗ H₂SO₄ cho ra Cu nhé

b) Từ trái qua phải : 

\(Al_2O_3+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

\(Al_2\left(SO_4\right)_3+3NaOH\rightarrow Al\left(OH\right)_3+3Na_2SO_4\)

\(2Al\left(OH\right)_3\xrightarrow[]{t^o}Al_2O_3+3H_2O\)

2) \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)

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

0,2 -->0,6--------->0,2------>0,3

a) \(m_{ddHCl}=\dfrac{\left(0,6.36,5\right)}{7,3\%}.100\%=300\left(g\right)\)

b) \(m_{ddspu}=5,4+300-0,3.2=304,8\left(g\right)\)

\(C\%_{AlCl3}=\dfrac{0,2.133,5}{304,8}.100\%=8,75\%\)

\(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)

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

       0,2        0,3                   0,1         0,3

a) \(m_{muối}=m_{Al2\left(SO4\right)3}=0,1.342=34,2\left(g\right)\)

b) \(V_{H2\left(dktc\right)}=0,3.22,4=6,72\left(l\right)\)

c)\(V_{ddH2SO4}=\dfrac{0,3}{3}=0,1\left(l\right)\)

 Chúc bạn học tốt

2 Al + 3 H2SO4 -----> Al2(SO4)3 + 3 H2
0,2  :     0,3           :        0,1          :   0,3     (mol)
nAl= \(\dfrac{5,4}{27}\approx0,2\) (mol)
a) mAl2(SO4)3 = 0,1.342 = 34,2 (g)
b) VH2 = 0,3.22,4 = 6,72 (lít)
c) VH2SO4 = \(\dfrac{0,3}{3}=0,1\) (lít)