Notez inmultirile cu * si fractiile cu /
a ) c=md*100/ms=>ms=md*100/c=200*100/10=2000g solutie intitiala
concentratia finala se dubleaza c1=2*10=20%
c1=md1*100/ms1=>ms1=md1*100/c1= 200*100/20= 1000g solutie finala (care trebuie evaporata )
b) concentratia finala scade la jumatate atunci este egala cu c1= 10/2=5%
mapa= ms-md=2000g-200g=1800g H2O initial
c1=md1*100/ms1=>ms1=md1*100/c1=200*100/5= 4000g H2O
mapa1=ms1- md1=4000g-200g=3800g H2O finala
m'H2O=mapa+mapa1=3800g-1800g=2000g H2O care trebuie adaugata