5. \(n_{ZnCl_2}=0,02\left(mol\right);n_{KOH}=0,05\left(mol\right)\)
ZnCl2 + 2KOH → Zn(OH)2↓ + 2KCl
0,02.......0,04............0,02...........0,04
\(n_{KOH\left(dư\right)}=0,05-0,04=0,01\)
Zn(OH)2 + 2KOH → K2ZnO2 + 2H2O
0,005...........0,01.......0,005
\(n_{Zn\left(OH\right)_2}=\left(0,02-0,005\right).99=1,485\left(g\right)\)
b) Ion trong dung dịch gồm :
K+ : 0,05 mol
Cl-:0,04 mol
ZnO22- : 0,005 mol
=> \(\left[K^+\right]=\dfrac{0,05}{0,1+0,4}=0,1M\)
\(\left[Cl^-\right]=\dfrac{0,04}{0,1+0,4}=0,08M\)
\(\left[ZnO_2^{2-}\right]=\dfrac{0,005}{0,1+0,4}=0,01M\)
6.a) \(n_{AlCl_3}=0,04\left(mol\right);n_{NaOH}=0,15\left(mol\right)\)
AlCl3 + 3NaOH → Al(OH)3↓ + 3NaCl
0,04.........0,12..........0,04..............0,12
\(n_{NaOH\left(dư\right)}=0,15-0,12=0,03\left(mol\right)\)
Al(OH)3 + NaOH →NaAlO2 + 2H2O
0,03...........0,03
\(n_{Al\left(OH\right)_3}=\left(0,04-0,03\right).78=0,78\left(g\right)\)
b) Ion trong dung dịch gồm :
Na + : 0,15 mol
AlO2- : 0,03 mol
Cl- : 0,12 mol
=>\(\left[Na^+\right]=\dfrac{0,15}{0,5}=0,3M\)
\(\left[AlO_2^-\right]=\dfrac{0,03}{0,5}=0,06M\)
\(\left[Cl^-\right]=\dfrac{0,12}{0,5}=0,24M\)