Răspuns:
Explicație:
ms1= 70g sol. NaOH , c1= 20%
ms2= 30 g sol .NaOH , c2=50%
c sol. care se obtine
- se afla md1
md1= c1 . ms1 : 100
md1= 20 .70 : 100= 14g NaOH
- se afla md2
md2= c2 . ms2 : 100
md2= 50 . 30 : 100= 15g NaOH
- se afla md total
md = md1 + md2
md= 14 + 15= 29 g NaOH
- se afla ms total
m = ms1 + ms2
ms= 70 + 30= 100g sol. de NaOH
- se afla c acestei sol.
c= md .100 : ms
c= 29 .100 : 100= 29%
