Question

Se amesteca 200g solutie 20% sare cu 200g. solutie 10 % sare si 200g apa. Ce concentratie procentuala va avea solutia obtinuta?

Answer 1

ms1=200g C1=20% ms2=200g C2=10% m apa.adaugata=200g ------------------------------ Cfinal=? ------------------------------ md1=(c1 x ms1)/100=20x200/100=40g md2=(c2 x ms2)/100=10x200/100=20g m apa.total=(ms1-md1)+(ms2-md2)+ m apa.adaugata=200-40+200-20+200=540g md final=md1+md2= 40+20=60g Cfinal=(md final x 100)/(md final+m apa.total)=60x100/(60+540)=6000/600 => Cfinal=10%