Density of the pure substances at 20 °C:

ϱB = 878,9 kg/m³
ϱT = 866,9 kg/m³ (S. 110/111 or 131 a. 143)

Density of the mixture:

ϱM = ϱB · wB + ϱT · wT = 878,9 kg/m³ · 0,25 + 866,9 kg/m³ · 0,75
ϱM = 869,9 kg/m³



The task

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