Diffusion and Distribution

Question 1

What is flux?

Answer 1

The number of molecules travelling through a cross-sectional area per second

Question 2

What is Fick’s First law?

Answer 2

Diffusion under steady state. Always positive.

Question 3

What is steady state?

Answer 3

Concentration gradient does not change over time

Question 4

What affects the diffusion coefficient?

Answer 4

Temperature
Pressure
Nature of the solute
Solvent properties

Question 5

What are the barriers to solute diffusion?

Answer 5

Intermolecular solvent-solvent interactions

Question 6

What is Fick’s Second law?

Answer 6

Diffusion that occurs under either steady state or non-steady state

Question 7

What is the partition coefficient?

Answer 7

Distribution of a solute between two immiscible phases. Is constant

Question 8

What is the difference between logP and logD?

Answer 8

LogP = partition coefficient
LogD = distribution coefficient

Question 9

What is the distribution coefficient?

Answer 9

Equilibrium ratio of all species in two immiscible solvents. Changes with pH

Question 10

What is the pH partition hypothesis?

Answer 10

That acids tend to accumulate in basic fluid compartments, and that bases tend to accumulate in acidic fluid compartments