Question

peste 200g solutie de concentratie 15% se adauga 150 grame apa .ce concentratie vaavea solutia obtinuta?

Answer 1

c=15%
ms=200g
c=$\frac{md}{ms}$×100⇒15=$\frac{md}{200}$×100=$\frac{md}{2}$⇒md=15×2=30g
c=$\frac{md}{ms}$×100=$\frac{30}{350}$×100=$\frac{3}{7}$×20=$\frac{60}{7}$=8,(571428)%