Răspuns:
e de steptat ca prin amestecrea celor doua solutii, sa se obtina o solutie cu o conc. cuprinsa intre 25% si 10%
c=mdx100/ms, unde ms= md+m,apa
ms1=100g
c1=25%
ms2=200g
c2=10%
c3?
c3=md3x100/ms3, unde md3= md1+md2
ms3= ms1+ms2= 100g+200g=300g
md1= c1xms1/100= 25x100/100g=25g
md2=c2xms2/100= 10x200/100g= 20g
md3=45g
c3= 45x100/300=15%
pentru a afla m,apa ,
stiu ca ms3= md3+m,apa--> m,apa= 300g-45g=255g
Explicație:
