Răspuns:
mₐ=35g
Explicație:
mₐ=masa de apa
C=concentratie
ms=masa de substanta
md=masa dizolvata
3.
C=30%
ms=50g
⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻
mₐ=?
⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻⁻
C=md/ms*100 <=> 30=md/50*100 => md= 30*50/100=15g
ms=md+mₐ <=> 50=15+mₐ => mₐ=50-15=35g apa
