Question

Problema suna cam asa :Care este masa de apa adaugata la 130g solutie de concentratie 80% pentru a obtine o substantavde concentratie 60%
Cine ma poate ajuta repede.?

Answer 1

ms1=130g
c1=80%

c=mdx100/ms-->md1=c1xms1/100=0,80x130g=104g

in a doua solutie se modifica doar ms,prin adaugarea apei la 130g solutie
deci, md2=md1=104g
        ms2= ms1+mapa= 130+ m,apa

c2= md2x100/ms2
60/100= 104/(130+m,apa)
104x100= 60x(130+m,apa)..........................calculeaza m,apa !!!