IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => IGCSE/ GCSE => Sciences => Topic started by: @d!_†oX!© on November 15, 2009, 07:54:34 am
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According to the ms for oct/nov 2008 combustion of fossil fuels produces Carbon oxides, Nitrogen oxides and Sulfur oxides
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=SUdDU0UvQ2hlbWlzdHJ5L0NJRS8yMDA4IE5vdi8wNjIwX3cwOF9xcF8xLnBkZg==
question 33
And now according to the ms for oct/nov 2006 combustion of fossil fuels produces Carbon oxides, and Sulfur oxides but not Nitrogen oxides....
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=SUdDU0UvQ2hlbWlzdHJ5L0NJRS8yMDA2IE5vdi8wNjIwX3cwNl9xcF8xLnBkZg==
question 31
so now what to do?? :o :o
I think we should follow what oct/nov 2008 says because that's the latest one....i thought i should let all of u know about this... ::) ::)
so please give ur comments about what u think the right answer should be.... ;D
:) :) ~~~~~~~~~~~ :) :)
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It's all in the wording of the question (I would assume).
The first one asks, which gases are formed "because of the combustion of fossil fuels" but the second one asks for the "products" of the combustion of fossil fuels.
Yeah, it tripped me up too.
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didn't get u dude....i mean what difference does it make btwn.
gases formed by combustion and products of combustion??
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didn't get u dude....i mean what difference does it make btwn.
gases formed by combustion and products of combustion??
Products of combustion implies that these must be formed as products of combustion. Oxides of Nitrogen aren't formed as products.
However byrning of fossil fuels in car engines increases the temperature so Nitrogen and Oxygen react to form Nitrogen oxides. So it is indirectly because of burning fossil fuels but not a product of combustion of fossil fuels.
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well i knew that eightas and Thanks for reminding me....but cud u plss check the papers for the exact question...cuz if a question is asked to us in the exams...then wat answer do they expect??
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CIE sux. >:(