1)
md = 2 parti
ms = md + m.apa = 2 parti + 6 parti = 8 parti solutie
c% = md x 100 / ms = 2 x 100 / 8 = 25%
2)
md = masa solut = 2 parti
ms = 5 parti
c% = md x 100 / ms = 2 x 100 / 5 = 40%
3)
md =? g
ms = 120 g
c% = 8%
c% = md x 100 / ms
=> md = ms x c% / 100 = 120 x 8 / 100
=> md = 9,6 g azotat de potasiu