Question

Care concentratia finalã a unei solutii care se obtine prin amestecarea a 300 g
solutie NaCI 10% cu 450 g solutie NaC1 5%.

Answer 1

Răspuns:

Explicație:

ms1=300g sol. NaCl

c1=10%

ms2= 450g sol. NaCl

c2=5%

c3=?

md1= c1 . ms1 :100

md1= 10 . 300 : 100 = 30g NaCl

md2= c2. ms2 :100

md2= 5 . 450 : 100 =  22,5 g NaCl

md3= md1 +md2

md3= 30 + 22,5= 52,5 g NaCl

ms3= 300 + 450= 750g sol. de NaCl

c3= md3 .100 : ms3

c 3= 52,5 .100 : 750= 7%