Question

Do 200 cm ³ roztworu o stężeniu 15% i gęstości 1,2g/cm ³ dodano 60 cm ³ wody. oblicz stężenie procentowe.

Answer 1

Vr₁ = 200 cm³
d r₁ = 1,2 g/cm³
C%₁ = 15 %
C%₂= ?
mr₁ = ?
ms₁ = ms₂
mr₂ = mr₁+mw
dw=1g/cm³
Vw = 60cm³
mw = dw * Vw = 1g/cm³*60cm³= 60g
mr₁ =Vr₁ *d r₁= 200 cm³*1,2 g/cm³= 240g
C% = ms*100%/mr
ms₁= 240g*15%/100% = 36 g
mr₂ = 240g + 60 g=300 g
C%₂= 36g*100%/300g = 12%