Răspuns:
Explicație:
ms1=400g sol. HCl
c1= 20%
ms2= 300g sol HCl
c2=40%
mapa ad.= 100g
c3=?
-se afla md1 si md2
md1= c1 . ms1 : 100
md1= 20 .400 : 100= 80g HCl
md2= 40 .300 : 100= 120g HCl
- se afla md3
md3= md1 + md2
md3= 80 + 120= 200g HCl
- se afla ms3
ms3= ms1 + ms2 + mapa ad.
ms3= 400 + 300 + 100= 800g sol. HCl
-se afla c3
c3= md3 .100 : ms3
c3= 200 . 100 : 800= 25 %