Question

Calculati cantitatea de oxid de calciu necesara pentru a obtine 500 kg de apa de var ,concentratie 5%

Answer 1

Cp=md/ms*100=>md=Cp*ms/100=5*500/100=25kg Ca(OH)2

56kg...................74kg
CaO + H2O = Ca(OH)2
x=..........................25kg
x=25*56/74
x==18,9189 kg CaO

Answer 2

c = md/ms * 100
md = ms * c/100
md = 500*5/100
md = 25 kg 
CaO + H2O = Ca(OH)2
56 g CaO...................74 g Ca(OH)2
x kg CaO....................25 kg Ca(OH)2
x = 18,92 kg