Ta có: \(n_{H_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)

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

a, \(n_{Al}=\dfrac{2}{3}n_{H_2}=\dfrac{1}{6}\left(mol\right)\Rightarrow m_{Al}=\dfrac{1}{6}.27=4,5\left(g\right)\)

b, \(n_{H_2SO_4}=n_{H_2}=0,25\left(mol\right)\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,25}{0,2}=1,25\left(M\right)\)

c, \(n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{3}n_{H_2}=\dfrac{1}{12}\left(mol\right)\)

\(\Rightarrow m_{Al_2\left(SO_4\right)_3}=\dfrac{1}{12}.342=28,5\left(g\right)\)

\(a,n_{Na_2SO_3}=\dfrac{12,6}{126}=0,1mol\\ Na_2SO_3+2HCl\rightarrow2NaCl+SO_2+H_2O\\ n_{SO_2}=n_{Na_2SO_4}=0,1mol\\ V_{SO_2}=0,1.22,4=2,24l\\ b,n_{HCl}=0,1.2=0,2mol\\ C_{M_{HCl}}=\dfrac{0,2}{0,15}=\dfrac{4}{3}M\\ c,n_{NaOH}=\dfrac{40.10}{100.40}=0,1mol\\ T=\dfrac{0,1}{0,1}=1\\ \Rightarrow Tạo,NaHSO_3\\ NaOH+SO_2\rightarrow NaHSO_3\\ m_{NaHSO_3}=0,1.64+0,1.40=10,4g\)

\(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

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

\(\left(mol\right)\)       \(0,2\)     \(0,6\)         \(0,2\)           \(0,3\)

\(a.m=0,2.27=5,4\left(g\right)\\ a=\dfrac{36,5.0,6.100}{7,3}=300\left(g\right)\\ b.\)

\(AlCl_3-\) Nhôm clorua

\(m_{AlCl_3}=0,2.133,5=26,7\left(g\right)\\ c.m_{H_2}=0,3.2=0,6\left(g\right)\)

\(n_{H_2}=\dfrac{6.72}{22.4}=0.3\left(mol\right)\)

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

\(0.2........0.6..........0.2.............0.3\)

\(m_{Al}=0.2\cdot27=5.4\left(g\right)\)

\(m_{HCl}=0.6\cdot36.5=21.9\left(g\right)\)

\(\Rightarrow m_{dd_{HCl}}=\dfrac{21.9}{7.3\%}=300\left(g\right)\)

\(m_{AlCl_3}=0.2\cdot133.5=26.7\left(g\right)\)

( Nhôm clorua ) 

\(m_{H_2}=0.3\cdot2=0.6\left(g\right)\)

Chọn C

Đáp án C

Bài 1:

\(n_{HCl}=2.0,16=0,32\left(mol\right);n_{H_2}=\dfrac{3,584}{22,4}=0,16\left(mol\right)\)

PTHH: Mg + 2HCl → MgCl₂ + H₂

PTHH: Fe + 2HCl → FeCl₂ + H₂

\(m_{H_2}=0,16.2=0,32\left(g\right)\)

\(m_{HCl}=0,32.36,5=11,68\left(g\right)\)

Theo ĐLBTKL ta có: \(m_{MgCl_2+FeCl_2}=1,4+11,68-0,32=12,76\left(g\right)\)

Bài 12:

Theo ĐLBTKL, ta có:

\(m_{hhkl}+m_{O_2}=m_{hh.oxit}\\ \Leftrightarrow11,9+m_{O_2}=18,3\\ \Leftrightarrow m_{O_2}=18,3-11,9=6,4\left(g\right)\\ n_{O_2}=\dfrac{6,4}{32}=0,2\left(mol\right)\\ V_{O_2\left(đktc\right)}=0,2.22,4=4,48\left(l\right)\)

Đáp án A