Aerosols In The Atmosphere

Question 1

Aerosols

Answer 1

Suspensions of sold or liquid droplets in a gas that are thermodynamically unstable and subject to coagulation

Question 2

Acid gases

Answer 2

Trace gases that dissolve in water to produce an acid solution

Question 3

Equilibrium approach

Answer 3

Can write equilibrium constant for dissolution of gases in water
Rearrange for Henry’s law

Question 4

Kinetic approach

Answer 4

Consider combination of adsorption/desorption in equilibrium at surface of water droplet: A(g) = A(ads)
and diffusive absorption into bulk of droplet: A(ads) -> A(aq)
Larger Pa = more readily saturated

Question 5

Langmuir adsorption isotherm

Answer 5

bA, assumes fixed conc of adsorbed species in full mono layer

Question 6

Boundary conditions for Fick’s second law

Answer 6

For gas adsorbing at water droplet surface assume conc at surface (r=r0) is fixed and that it is 0 at the centre of the droplet (r=0)

Question 7

Value of b in diffusion coefficient equation

Answer 7

6 for molecules larger than solvent
4 for molecules same size as solvent
3 form molecules smaller than solvent

Question 8

What is Arrhenius-like behaviour of diffusion coefficient based on

Answer 8

Viscosity of liquid decreases with temp in an exponential manner