Đáp án:

26.

$2Al + 3Cl_2 \xrightarrow{t^0} 2AlCl_3$

$Zn + 2HCl \to ZnCl_2 + H_2$

$3Fe + 2O_2 \xrightarrow{t^0} Fe_3O_4$

`2Al(OH)_3 + 3H_2SO_4 \to Al_2(SO_4)_3 + 6H_2O`

27.

`CM={0,15}/{0,2}=0,75M`

28.

`n={V}/{22,4}={16,8}/{22,4}=0,75mol`

29.

`a) Zn + 2HCl \to ZnCl_2 + H_2`

`b) n_{Zn}=13:65=0,2 mol`

Theo pt: `n_{H_2}=n_{Zn}=0,2 mol`

`=> V_{H_2}=0,2.22,4=4,48l`

c) Theo pt: `n_{HCl}=2.n_{Zn}=2.0,2=0,4 mol`

`=> m_{HCl}=0,4.36,5=14,6g`

`=> m_{ddHCl}={14,6}/{0,1}=146g`

30.

`a) Fe + 2HCl \to FeCl_2 + H_2`

`b) n_{Fe}=2,8:56=0,05 mol`

Theo pt: `n_{H_2}=n_{Fe}=0,05 mol`

`=> V_{H_2}=0,05.22,4=1,12l`

c) Theo pt: `n_{HCl}=2.n_{H_2}=2.0,05=0,1 mol`

`=> m_{ddHCl}={0,1.36,5}/{0,1}=36,5g`