Răspuns:
ex.5. ms1=400g
c1=15%
c1=m1×100ms1->m1=15×400/100g=60g
c2=25%
m2=ms1
ms2=ms2×100/c2=60×100/25g=120g
m(apa evaporata)->ms1-ms2=400g-120g=280g
ex1 .
Vs=400cm^3
p=1,225g/cm^3
c=20%
md=?
p=ms/Vs
ms=p×Vs
ms=400×1,225
ms=490g
c=md/ms ×100
md=c×ms/100
md=20×490/100
md=98g(soda caustica)
ex.
