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CH3041
DILUTE
CONCENTRATIONS
• It is more convenient to use the scale: parts per X for low conc. gases:
parts per million ppm 1
/ 106
parts per billion ppb 1
/ 109
parts per trillion
ppt 1
/ 1012
• 1 ppm O3 means 1 mole(cule) of O3 in every
106 mole(cules) of air. V = n RT/P
106 mole(cules) of air. V = n RT/P
•1
ppmv O3 means 1 cm3 of O3 in 106 cm3 air.
• 1
ppm DDT in water means 1 mgDDT /
1 LH2O
(based on 1mg /1 kg = 1 mg / 106 mg)
(based on 1mg /1 kg = 1 mg / 106 mg)
• 1% = 1/100 = (1 / 106) x 104 \ 1% = 1ppm x 104
