Question

calculati concentratia unei solutii prin amestecareaa 300g solutie 10% cu 20g solutie 20%

Answer 1

300g.....100%
Xg.....10%
=>x=300x10:100=30g

20g....100%
Yg......20%
=>y=20x20:100=4g
=>x+y=30+4=34g(masa substantei pure)
Masa totala=320g

100%....320g
Z%......34g
=>z=34x100:320=10,625%

Bafta la scoala:)