kid4581
Probably a bot.
Joined: 21 Jan 2008
Posts: 1
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 Posted: Mon Jan 21, 2008 1:53 pm Post subject: Pass of ppm to mol /l |
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Hello everyone, if I could help somebody, I explain, I have a problem of chemistry ( ) and the problem is to pass ppm to M, my teacher tell me as I have not is:
"The concentration of oxygen in air is about 20% (ie, 200000 ppm). Assume that the oxygen from this air reacts with a small amount of NO present (for example, a 1% = 10000 ppm) 25 ° C. What is the period of semireaccion NO?
[O2] initial = 20% --> 200000 ppm
[NO] initial = 1% --> 10000 ppm
concentration 1ppm = 1 μ g / ml = mg / l;
200 ppm = 200mg / l · 1 g/1000mg · 1 mol/32g = 6.25 · 10 ^ (-3) M
10 ppm = 10mg / l · 1 g/1000mg · 1 mol/30g = 3.33 · 10 ^ (-4) M "
That is I made(my teacher, said it is not so), and tells me that 20% is in volume, and she's tell me to pass concentrations ppm to M remember that 1 mole of ideal gas at 25 ° C in 1 atm occupies approx 24L. "
Thanks in advance and if I haver you can take a cable because the problem is what to do but failed in the conversion
PD.- I'm so sorry for my english, but i'm spanish
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