a.
Vs = 1,5 L = 1500 mL, ro = p = 1,2 g/mL
p = ms/Vs => ms = pxVs = 1,2x1500 = 1800 g
md = 450 g
=> dupa fierbere Vs.final = 1500/2 = 750 mL , p = 1,45 g/mL
=> ms.final = pxVs.final = 1,45x750 = 1087,5 g
c%final = mdx100/ms.final = 450x100/1087,5 = 41,38%
b.
m.apa.evaporata = ms - ms.final = 1800-1087,5 = 712,5 g apa