Question

Aflati concentratia procentuala a solutiei care se obtine prin adaugarea unei concentrati de apa : a) se dau 100 g solutie 25% si se adauga 200 g apa

Answer 1

c=md .100:ms       se calculeaza md sol.
md=c.ms:100
md=25.100:100=25g
 se calculeaza ms final
ms final=100+200=300 g sol
se calculeaza concentratia sol finale
c=25.100:300
c=2500:300
c=8,3 la suta