c=mdx100/ms
pentru a treia solutie,
c3= md3x100/ms3, unde md3=md1+md2
ms3=ms1+ms2+m,apa
mapa= 500g
ms1=200g
md1= c1xms1/100= 50x200/100g=100gH2SO4
ms2= roxv2=500mlx1,42g/ml= 710g
md2= 50x710/100g= 355g
md3= 455g
ms3=1410g
c3= 455x100/1410=................calculeaza !!!!!