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Reaction mechanism, formation of acid rain?


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#1 anabourdais

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Posted 15 March 2007 - 05:22 PM

I'm trying to write out the reaction mechanism for the formation of acid rain from atmospheric nitrogen. I know the general equations to go through but when it comes to showing the movement of electrons with 'curly arrows' I get stuck!
so far this is what i have:

1. O + N≡N → N=O + N

2. N + O=O → O + N=O

3. 2N=O + O=O → 2O=N=O

4. N=O + O=O=O → O=O + O=N=O

5. O=N=O + O-H → H=O=N=O

O

I know that electrons from the triple bond of the nitrogen in step 1 move to one N atom and this means that the O is attracted to the other N and they form NO.
I can also complete number 2 (i think) as it is the same as above, with different compounds. It's number 3 onwards that cause the problems.

any help appreciated!
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#2 woelen

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Posted 15 March 2007 - 06:47 PM

NO is a radical, it attaches to O2, forming O2-NO, the latter being unstable and loosing an oxygen atom and leaving behind an NO2 radical.

The structure of ozone is not O=O=O, it only can be described by means of resonance structures. The mechanism for reaction of NO with O3 is quite similar to that for reaction between NO and O2.

In the latter mechanism, nitric acid is formed, but the OH-group attaches to the N-atom through a single bond, so no H=O=N(=O)=O, but H-O-N(=O)=O.
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#3 anabourdais

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Posted 15 March 2007 - 07:13 PM

so if you had to write out the structure for ozone, would it be represented with O-O=O or O-O-O with dotted lines representing the resonance structure?

Thank you very much for the above explanation - I think I'm getting there with understanding!!
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#4 grifter

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Posted 24 March 2007 - 10:42 AM

Okay I'm guessing your doing the open book (I am to)
In answer to your question; I'm pretty sure ozone is represented as O=O-O
hope this helps!
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#5 sadie

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Posted 24 March 2007 - 03:32 PM

i also really need help on the question: give a detailed account of the reaction mechanisms involved in the formation of acid rain from atmospheric nitrogen. i'm finding it really hard to discover. can anyone explain in a different way to that above?
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#6 Jo

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Posted 25 March 2007 - 12:55 PM

hey i'm doing my open book atm and im stuck on the same question. all of those equations have confused me! can anyone explain it simply then i can try and build it up a bit from there... =)
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#7 grifter

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Posted 25 March 2007 - 04:49 PM

I know what you mean, this question is tricky, the way I did it was similar to the one posted above, I just outline the reaction N2(g) + O2(g) --> 2NO(g) (don't forget lightning/ large amounts of energy above the arrow) i then went on to discuss how the newly formed NO reacts with O2 to form NO2
and then how that reacts with H2O to form HNO3(aq) + NO(g)
you might also want to include how nitric acid is formed, with the OH-group attaching to the N-atom through a single bond, H-O-N(=O)=O
it all balances quite neatly.......honest :rolleyes:
anyway, good luck guys
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#8 Jo

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Posted 26 March 2007 - 08:19 PM

cheers :-) thats alot easier to understand!

i know i dont have much time left to finish this but im not at all motivated, and i have physics coursework as well.. ahhh! on top of that i have to go to cambridge uni for 2 days, i have no chance! haha

good luck everyone!
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#9 grifter

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Posted 27 March 2007 - 08:23 PM

im in pretty much the same position as you, my physics coursework is a total nightmare !!! (i live near Bristol too)
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The Grifter strikes again!

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#10 jellybaby

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Posted 27 March 2007 - 09:51 PM

OK i'm confused [also doing the open book and hating it!]. In the 1st equation of the original post, is the O meant to be a radical? If yes, where does it come from [only explanation i can find is the breakdown of NO2?] and if not, how is it just an O on its own??
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#11 Ducky

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Posted 28 March 2007 - 04:29 PM

Yeah, open book is very difficult, but i nearly got it! In answer to your question jellybaby "In the 1st equation of the original post, is the O meant to be a radical? If yes, where does it come from [only explanation i can find is the breakdown of NO2?] and if not, how is it just an O on its own??" it comes from the second step, it produces a 'bi radical', that is when there is 2 radicals in the 1 atom, and the O=N so it would look like,
.
:o: + O=N
'
Radicals, being at the top and bottom of this, that is going into Degree level chem. FUN!!! Hope this helps!! Good luck!!! :D
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#12 egeinus

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Posted 31 March 2007 - 10:39 AM

the O radicals are produced by halogens in thee atmosphere (such as Cl), NO and UV sunlight. this happens in the 10.1 E14 to 14 E14 Hz region.

this information was from the "Salters Advanced Chemistry Chemical Storylines" book

hope this answers your question.
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#13 ღ*Princess*ღ

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Posted 31 March 2007 - 04:07 PM

hiya ..im new here..:-) eeerrrmm..i think u all doing chemistry.. ive got an open book paper..and iam kinda stuck wiv the mechanism of acid rain from atmospheric nitrogen..can any1 help plz...coz i dunno wat to write exactly ..i mean the structure and that..and wat do i search 4...any help will be very much appreciated ..thanx..
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#14 ღ*Princess*ღ

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Posted 31 March 2007 - 08:29 PM

u know the last bullet point ..it says "identify the problems that scientists still need to solve in reducing harmful vehicle emissions" can sum1 giv me examples of them...??!!! ;) and if any1 find a gud website for this open book paper plz post it..this is a gud website for salters revision www.4college.co.uk ..i really need help guys ive just started this 2day..and we wer given it on wed..so i havn't got long left:eek: ..its a long story..i couldn't start it coz i had other courseworks:mad: at the same time and i had to hand them in b4 da holidays.!!!!
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#15 Jo

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Posted 31 March 2007 - 09:08 PM

hey almost finished my open book now!

over the word limit tho, just wondering do sub headings count?

and if you put something like "Fig 3. lambda sensors balance the mixture etc etc" under a picture would that count?

probably a stupid question but hey =)

loads of people in my chem class said "JO! i saw your post on that forum! =O" haha ace
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"I'd tap that..."

#16 ღ*Princess*ღ

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Posted 1 April 2007 - 11:53 AM

as far as i know..figure quotes/notations are not counted and also bibliography ..im not sure abt sub headings..but i think u do count them??!![/COLOR]


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#17 misschloebet

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Posted 1 April 2007 - 01:19 PM

Ok I am struggling with this question as well. I am retaking the open book paper, and wonder how much detail we are supposed to go into? It is only worth 4 marks, and my class personally have not covered the tricky chemistry of the original post.
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#18 ღ*Princess*ღ

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Posted 1 April 2007 - 03:58 PM

yh das wat i was thinkin..but its prob wat we hav to do...i don't get y has nitrogen got 3 bonds in equation 1 ???? sorry if this is stupid!!??? :s eerrrmm...if its worth 4 marks then im spedin 154 words approx on it...but das excludin diagrams.. this is ma first time doing this paper and ive only got 3 days includin 2day to finish it ..ive only started yesterday..i havn't done much... :( :S oopppssss ..!!! concentrate on the first and 3rd questions..u know on the first one it says "explain diff types of engines.....write more abt that than the first sentence and for the third one explain the fisrt bullet point prop and the second one would be in detail too but not as much as the first and for the third one u would hav less than both...i have divided ma 1000 words..ive got 346 words for the 1st question, 154 for the second, 385 for the 3rd and 115 for the 4th....lol..i hope that helps??!!
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#19 ღ*Princess*ღ

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Posted 2 April 2007 - 02:51 PM

hey guys..and plz answer this time..lol...wat has the temperature got to do with the type of emission?
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#20 Lenny

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Posted 6 April 2007 - 12:36 PM

i was searching about the acid rain question and found this forum! i never thought about different schools having already started the same paper!

when i first read the question i thought it was about box 2 on page 4, but then i saw it said atmospheric nitrogen :mad:

so are they asking how acid rain is formed even when there arent any car emissions??
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