Question

Va rog rezolvarea pana la ora 13. Plsssss!!! ​

Answer 1

Formulele de baza pe care trebuie sa le stii: c=md/ms * 100

si ms= md + mapa

c= concentratie; md = masa dizolvat; ms = masa solutie

1. c=(md/(md+mapa)) * 100 = 20 %

2. c= 20%

md = ?

m apa=?

ms = 400g

c/100 = md/ms

md= c*ms/100 = 20*400/100 = 80g

mapa = ms - md = 400 - 80 = 320

3. ms1= 200g

c1= 10%

ms2= 300g

c2= 20%

cf=?

cf= mdf/msf * 100

mdf = md1 + md2 = c1*ms1/100 + c2*ms2/100 = 10*200/100 + 20*300/100

      = 20+60 = 80 g

msf= ms1 + ms2 = 200+300 =500 g

cf= mdf/msf * 100 = 80/500*100 = 16%