Question

Ce cantitate de zahar se va dizolva in 475 grame apa pentru a se obtine o solutie de concentratie 5%?

Answer 1

realtia folosita
c=mdx100/ms, unde ms= md+m,apa

c= mdx1oo/( md+m,apa)
inlocuieste c=5%
                  m,apa= 475g   calculeaza  md

Answer 2

C=(md)/(md+mH2O)*100=>C(md+mH2O)=md*100 => C*md+C*mH2O=md*100=>C*mH2O=md*100-C*md=>C*mH2O=md(100-C) => md=(C*mH2O)/(100-C)=(5*475)/(100-5)=2375/95=25g zahăr