chornedsnorkack
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What is ppm?
Since 1 bar is 100 000 Pa, is 1 Pa partial pressure by definition 10 ppm?
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DraconicAcid
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Only if the total pressure is 1 bar.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Texium
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1 ppm = 0.0001%
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chornedsnorkack
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Does this depend on molar mass?
Is ppm, as quoted in danger limits, smell thresholds, et cetera, in ml per million ml (m3), thus mPa per kPa? Or is it mg/kg?
When mercury at 20 C has saturated vapour pressure of 0,17 Pa, does it mean saturated mercury fumes are 1,7 ppm? Or are they 12 ppm (because Hg is
also about 7 times the molar mass of air)?
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Texium
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For air, I believe ppm is generally defined as volume of selected gas / total volume of air. For liquids, it’s expressed as mg solute / kg solvent
(and for dilute aqueous solutions, often serves as a shorthand for mg/L)
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barbs09
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We use ppm (parts per million) as a useful measure of concentration of gold in ore, which we also interchange with grams per tonne i.e., 1ppm =
1g/tonne i.e there are 1 million grams in a metric tonne.
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bariumbromate
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if you have 1 ppm hydrogen cyanide in the air for every million units of air there will be 1 unit of cyanide
[Edited on 3-6-2025 by vertexrocketry]
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Sulaiman
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at low concentrations, molar fraction is the same as volumetric fraction (for ideal gasses)
for weight ratios you need to know molecular weights,
the equivalennt m.w. of air is about 29 g/mol
CAUTION : Hobby Chemist, not Professional or even Amateur
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