ATMOSPHERIC CHEMISTRY AND PHYSICS: FROM AIR POLLUTION TO CLIMATE CHANGE Third Edition John H. Seinfeld California Institute of Technology Spyros N. Pandis University of Patras and Carnegie Mellon University John Wiley 2015
1.4
CH3SCH3 concentrations range from 250 to 500 ng m-3 (0.25 to 0.50 μg m-3).
ξ CH SCH (ppm) = 3
3
=
RT pM CH 3SCH 3
[CH3SCH 3 ] (μg m −3 )
(8.314) (298) (0.25) = 9.86 × 10-5 ppm
(1.0133 × 10 ) 5
= 0.0986 ppb At 0.5 μg m-3, ξ CH 3SCH 3 = 0.197 ppb
1.5 ⎛ 3.7879 L ⎞ ⎛ 1000 cm 3 ⎞ ⎛ 0.85 g ⎞ ⎟⎟ ⎜ ⎟⎟ ⎜⎜ 500 gallons ⎜⎜ = 1,609,857.5 g Gasoline 3 ⎟ L ⎝ gallon ⎠ ⎝ ⎠ ⎝ cm ⎠
C: 12.01 g/mol H: 1.01 g/mol O: 16.00 g/mol gasoline (C8H18) = [8(12.01) + 18(1.01)] g/mol = 114.26 g/mol CO2: (12.01 + 2·16.00) g/mol = 44.01 g/mol ⎞ ⎛ 44.01 g CO 2 ⎞ ⎛ 1 kg ⎞ ⎟⎟ ⎜⎜ ⎟⎟ ⎟⎟ ⎜⎜ 1 mol gasoline 1 mol CO 1000 g ⎠ ⎠⎝ ⎠⎝ 2 ⎠⎝ ⎞⎛
⎛
(1,609,857.5 g )⎜⎜ 1 mol gasoline ⎟⎟ ⎜⎜ 8 mol CO 2 ⎝
= 4960 kg CO2
114.26 g
1.6 Mass of the atmosphere = 5.148 × 1018 kg = 5.148 × 1021 g Moles of the atmosphere = 5.148/29 × 1021 = 1.77 × 1020 mol air Moles of 1 ppm CO2 = (10-6) (1.77 × 1020) = 1.77 × 1014 mol CO2 Mass of 1 ppm CO2 = (1.77 × 1014 mol CO2) (44 g/mol) = 7.8 × 1015 Mass of carbon = (7.8 × 1015) (12/44) = 2.1 × 1015 g = 2.1 Pg C Current mass of C in atmosphere = (2.1) (400) = 840 Pg C