Minimals: Diffusion

Question 0

What is the relationship between the absolute temperature (T) and the average kinetic energy of a molecule (E) in a system containing monatomic gas in thermal equilibrium

Answer 0

E= 3/2 KT

K is Boltzmann constant

Question 1

Define frictional force acting on a molecule with velocity v in an aqueous environment

Answer 1

Ff=fv

F is form factor

Question 2

What is diffusion

Answer 2

Net flow of material propelled by brownish motion due to a gradient of chemical potential

Question 3

What is the physical meaning of the diffusion constant

Answer 3

The amount of material transported through a unit surface area in unit time at a unit concentration gradient. It characterize the mobility of molecules.

Question 4

What is the unit of diffusion constant

Answer 4

M square / s

Question 5

How does the diffusion constant (D$ depend on temperature (T) and the radius (r) of a spherical molecule

Answer 5

D~ T/r

Question 6

Write down the equation describing the relationship between the diffusion constant(D)cans the form factor (f)

Answer 6

D= KT/f
K is Boltzmann constant
T is absolute temperature

Question 7

Which parameters tend toward spatial equilibrium during a diffusion process

Answer 7

The chemical potentials of the components

Question 8

Write down vant Hoffs law

Answer 8

Pi=osmotic pressure=cRT
R is the universal has constant
T is the absolute temperature
C is the molar concentration of the material in the solution

Question 9

What is osmosis?

Answer 9

Flow of the solvent to a concentrated solution from the more dilute one, if the two compartments are separated by a semiprermeable membrane. This material flow decreases the concentration gradient between the two solutions.

Question 10

What is the osmotic pressure

Answer 10

It is the pressure which is able to prevent the solvent flow from the pure solvent to the solution through the semipermeable membrane