SC 07 SCIENCE - Combustion or Decomposition? (1 Viewer)

Fortify

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Was it Combustion or Decomposition?

I Put combustion cos of the heat, but there was no oxygen or oxidiser -.-".

Some Friends told me decomposition..
 

Lucy-Maexx

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I put decomposition.
Combustion: fuel + Oxygen --> Carbon dioxide + water
 
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amberangel

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Either way.

I wrote mine in in pencil, actually, so I dont think I'll be getting anything for it anyway. Meh. -_-;

Why worry over it? It's gone and over, not like I can change it now.
 

Adammmk

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I wrote combustion as soon as i saw heat
It looks like I was wrong....
Wasnt part of the result an oxide?
 

kkwok25

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i wrote combustion too. yeah i remember part of it was oxide and thats why i put combustion.
 

zenophobia

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I put combustion... what was the exact question, I can't remember it?

I do remember though that decomposition didn't even cross my mind.
 

ahhliss

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Same! I don't know why I didn't think of decomposition! I feel stupid >.<"
 

Fortify

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ahhliss said:
Same! I don't know why I didn't think of decomposition! I feel stupid >.<"
Same here! Decomposition didn't even pop up.

Found why it was Decomposition:

Thermal decomposition means to break down substances into two or more substances by heat (usually endothermic reactions) e.g.
  • The decomposition of calcium carbonate (limestone) into calcium oxide (lime) and carbon dioxide in a high temperature lime kiln.
  • CaCO3(s) ==> CaO(s) + CO2(g)
 

kkwok25

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OOOOH thats why! damn. i thought it was decomposition at first, but then i guess it didnt really come to me lol. lost a mark! most of my frds got combustion too lol. that oxide bit confused me =.=
 

zenophobia

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Ooh, that was the question?

I was almost certain it was combustion... the other possibility was actually corrosion... Geez, I certainly got things mixed up.
 

Fortify

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zenophobia said:
Ooh, that was the question?

I was almost certain it was combustion... the other possibility was actually corrosion... Geez, I certainly got things mixed up.
The question was something like this:What type of reaction is "Copper Carbonate + Heat => Copper Oxide + Carbon Dioxide.

And also I don't think it was corrosion cos heat isnt a catalyst for corrsion (correct me if im rong).But was is a catalyst for corrosion.
 

zeleboy

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Fortify said:
The question was something like this:What type of reaction is "Copper Carbonate + Heat => Copper Oxide + Carbon Dioxide.

And also I don't think it was corrosion cos heat isnt a catalyst for corrsion (correct me if im rong).But was is a catalyst for corrosion.
By the way, you never write " + heat "

You write heat ontop of the arrow.
 

zenophobia

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My science teacher told the class today that Decomposition was the answer.

-1 for me!
 

militiaman

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Grrr, not particularly liking this answer as the correct answer should actually be thermal decomposition. As far as I can tell this is a fairly specific type of decomposition, not just a description of it.

Anyone else want to picket the Board of Studies with me? :burn:

jk
 

boxhunter91

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Hi guys. First Post.
I also had trouble with this question.
At first sight I thought combustion obviously because of the heat. But because the product didnt contain water it isn't combustion.
I believe decomposition could be answer but that would only be throught heat. Just having decomposition as an answer isn't correct because it just states the breaking down but not the actual process. Thermal decomposition is correct but decomposition isn't.
We asked our science teacher yesterday and we gave her the equation and she said impossible: decomposition. Combustion she said would only occur if product was metal-oxide + water which it wasn't. Therefore she said answer is corrosion.
To make sure I will ask my head teacher for science. See what she thinks.

BTW i put corrosion :D LOL nearly changed to Carbonate reaction :p
 

iCpurplehippos

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it's not combustion because there weren't any oxygen in it.
I put decompsition :S
 

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