Question

in ce cantitate de apa trebuie dizolvat 450 g sare pt a obtine o concentrantie de 9/100?

Answer 1

cp=md/ms *100

cp-concentratia procentuala
md-masa substantei dizolvate
ms-masa solutiei

ms=md+m H2O

9/100= 450/(450+m H2O) *100

9/100= 45 000/(450+m H2O)

450+m H2O= 100 *45 000/9

450 + m H2O= 100*5 000

450+ m H2O= 500 000

m H2O= 500 000 -450

m H2O= 499 550 g