Assumption: in a water / HC mixture, mass fraction is the same as volume fraction.

1

• Assumption in a water / HC mixture, mass
  fraction is the same as volume fraction.
• Example 1 99 kg HC (density 700 kg/m3) and 1 kg
  H2O (density 1000 kg/m3).
• Mass fraction of H2O 1/(991) 1
• Vol of HC 99/700 0.14143 m3
• Vol of H20 1/1000 0.001 m3
• Vol fraction of H2O (0.001)/(0.14143 0.001)
  0.7

2

• Example 2 70 kg HC (density 700 kg/m3) and 30 kg
  H2O (density 1000 kg/m3).
• Mass fraction of H2O 30/(7030) 30
• Vol of HC 70/700 0.1 m3
• Vol of H20 30/1000 0.03 m3
• Vol fraction of H2O (0.03)/(0.1 0.03) 23
• Assumption mass and volume fraction are the same
  is wrong.