Question

Peste 300 g solutie hcl de concentratie, se adauga 200 g apa. Concentratia solutiei rezultate devine 20%. Care a fost concentratia procentuala a solutiei initiale? Toata rezolvarea va rog

Answer 1

ms2=ms1+mapa=300+200=500g        ms2=500g
md=c2*ms2/100=20*500/100=100g    md=100g
c1/100=md/ms1         c1=md*100/ms1=100*100/300=33.3%
   c1=33.3%