L1 /
3
CH3041
ATMOSPHERE
Situations with significant interface effects:
1) Raindrop chemistry g-l
1) Raindrop chemistry g-l
2) Gas transfer to
oceans g-l
3) Aerosol chemistry g-s, g-l
1) Raindrops form in saturated air but their
volume is low relative to air - 10-6:1 (at 1g / m3)
volume is low relative to air - 10-6:1 (at 1g / m3)
• A gas has to be very
soluble in H2O to be found principally in rain. Henry’s
Law
• eg H2O2 KH = 105 mol l-1 atm-1 [i(aq)] =
pi KH
• Reaction in the
raindrop ‘increases’ [i(aq)].
eg. HCHO(aq) + H2O D
H2C(OH)2(aq) formaldehyde
K = [H2C(OH)2(aq)]
/ [HCHO(aq)] methylene glycol
Total[HCHO(aq)] = KH pHCHO(1 + K)
(some from dissolution some from reaction)
(some from dissolution some from reaction)
