rho=density, U=velocity, L=equivalent diameter, mu=viscosity
Cp=specific heat, mu=viscosity, k=thermal conductivity
mu=viscosity, rho=density, D=mass diffusivity
ν = speed
[m/s], length=m
Example 2: Sucrose
Statement: Sucrose, aka table sugar or granulated sugar, is a disaccharide. It is made
up of glucose and fructose and has a molecular formula of C12H22O11. Sucrose has a
high solubility in water. Consider a solution of two tablespoon (40 g) of sucrose in 100 g
of water.
Example 3: Iron (II) Sulphate
Statement: Ferrous sulphate has the molecular formula FeSO4. Its solution is typically greenish in
colour. A solution of FeSO4 contains 20 g of FeSO4 and 100 g of H2O. The molar mass of FeSO4 is
152 g mol−1 and of H2O, 18 g mol−1.
L1 = initial moles of liquid originally in still
L2 = final moles of liquid remained in still
x1 = initial liquid composition in still (mole fraction of A)
x2 = final liquid composition in still (mole fraction A)
Performing a material balance on A:
Initial amount in still = Amount left in still + Amount vaporized
We have,
xL = (x - dx) (L - dL) + y dL
xL = xL - x dL - L dx + dx dL + y dL
Neglecting the term dx dL, the equation reduces to:
L dx = y dL - x dL
Re-arranging gives the following:
Integrating from L1 to L2, and from x1 to x2,
Rayleigh Equation: