Se da:
ms = 200g sol. Ca(OH)₂
C = 5,6%
Se cere:
m Cu(OH)₂ = ? (g)
Rezolvare:
C = md/ms×100 ⇒ md = C×ms/100 = 5,6×200/100 = 11,2g Ca(OH)₂
MCa(OH)₂ = 74g/mol
n = m/MCa(OH)₂ = 11,2/74 = 0,151 moli Ca(OH)₂
Ca(OH)₂ + CuSO₄ ⇒ CaSO₄ + Cu(OH)₂↓
Reactie mol la mol, deci n Ca(OH)₂ = n Cu(OH)₂ = 0,151 moli
MCu(OH)₂ = 98g/mol
n = m/M ⇒ m = n×M = 0,151×98 = 14,832g Cu(OH)₂
