Question

1. Peste 200g solutie 15% se adauga 150g apa. Solutia se dilueaza sau se concentreaza ? Ce concentratie va avea solutia obtinuta?

2. Din 150 g solutie de concentratie 5% s au evaporat 25 g apa. Determina concentratia solutiei obtinute.

3. Peste 200g solutie de zahar de concentratie 20% se mai adauga 10 g zahar. Ce concentratie are solutia obtinuta.

VA ROG REPEDE...

Answer 1

1. C=md/ms*100 => md=C*ms/100 = 15*200/100 = 30g

ms final = md + mH2O adaugat = 200+150 = 350g sol

Daca se adauga apa intr-o solutie aceasta se dilueaza..

C final = md/msf*100 = 30/350*100 = Calculeaza !!

2. C=md/ms*100 => md=C*ms/100 = 5*150/100 = 7,5g 

ms final =  150 - mH2O evaporata = 150-25 = 125g

Cf = md/msf*100 = 7,5/125*100 = Calculeaza !!

3. C=md/ms*100 => md=C*ms/100 = 20*200/100 = 40g

md final = 40+m zahar adaugat = 40+10 = 50g zahar

ms final = ms + mzahar adaugat = 200+10 = 210g

Cf=mdf/msf*100 = 50/210*100 = Calculeaza !!