Nheo nheo caxamitaa 5,6

câu `5:C`

`n_{CaO}={11,2}/56=0,2(mol)`

`PTHH:CaO+H_2O->Ca(OH)_2`

`(mol)`  `0,2->`                       `0,2`

`400ml=0,4(l)`

`C_M Ca(OH)_2 ={0,2}/{0,4}=0,5(M)`

câu `6:B`

`n_{Fe_2O_3}=8/160=0,05(mol)`

`PTHH:Fe_2O_3+3H_2 \overset(t^o)(->)2Fe+3H_2O`

`n_{H_2}=3n_{Fe_2O_3}=3.0,05=0,15(mol)`

`=>V_{H_2}=0,15.22,4=3,36(l)`

Câu 5

$PTHH: CaO +H_2O \xrightarrow{} Ca(OH)_2$

$n_{CaO}=\dfrac{11,2}{56}=0,2(mol)$ 

$n_{Ca(OH)_2}=0,2(mol)$

$C_{M_{Ca(OH)_2}}=\dfrac{0,2}{0,4}=0,5M$ Chọn $C$

Câu 6

$PTHH: Fe_2O_3 +3H_2 \xrightarrow{to}2Fe +3H_2O$

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

$n_{H_2}=3n_{Fe_2O_3}=0,15(mol)$

$V_{H_2}=0,15 ×22,4=3,36(lít)$ Chọn$B$