Question

1.Peste 100g solutie 25% se adauga 200g apa ?
2.Peste 300g solutie 80% se adauga 40g substanta dizolvata
3.Peste 10kg solutie 50% se adauga 600g solutie 90% si 60g dizolvat


Repede va rog

Answer 1

c = md*100/ms
1) md1=100*25/100 = 25 g
md2=md1=25 g
ms2 = 100+200 = 300 g soluție
c2 = 25/300*100 = 8,33%
2)md1=300*80/100 = 240 g
md2=md1+40=280 g
ms2 = 300+40 = 340 g soluție
c2 = 280/300*100 = 93,33%
3)md1=10*50/100 = 5 kg
md2=600*90/100 = 540g = 0,54 kg
md3 = 0,54+0,5+60/1000= 5,6 kg
ms3 = 10+0,6+0,06= 10,66 kg soluție
c3 = 5,6/10,66*100 = 52,32%