Dane
Cp1 = 50 %
V1 = 300 cm3
d1 = 1,3 g/cm3
Cp2 = 68 %
MH2O = ?
-masa roztworu 50 % - m1:
d = m/v
m1 = d 1x V1
m1 = 300 cm3 x 1,3 g/cm3 = 390 g
- masa substancji:
Cp 1 = ms x 100%/m1
ms = Cp x m1/100%
ms = 50 % x 390 g/100%
ms = 195 g
-masa roztworu 68 %- m2:
Cp2 = ms x 100% / m2
m2 = ms x 100%/Cp2
m2 = 195 x 100%/ 68%
m2 = 286,7 g – masa roztworu 68%
mH2O = m1 –m2
mH2O = 390 – 286,7 = 104 g