Comments on: O Level Chemistry – Mini Series on Tough MCQs Part 4

By: sam

sam — Fri, 11 Nov 2011 13:00:05 +0000

so what is the correct answer?

By: Matthew

Matthew — Thu, 10 Nov 2011 15:45:36 +0000

For the portion of:
‘Carbon on the other hand reacts with Oxygen to form Carbon Dioxide so Oxygen changed from an oxidation state of 0 to 2- so it is reduced and Carbon should be a reducing agent’,
rather than seeing it as oxygen losing 2 electrons, it can be seen as carbon gaining 2 oxygen atoms and therefore being oxidised.

By: Fixxa

Fixxa — Sun, 16 Oct 2011 10:14:32 +0000

carbon monoxide is the reducing agent because it reduces Fe2O3 to molten iron (Fe) and takes up oxygen itself and becomes carbon dioxide. This is why it is the reducing agent.

By: A

Tue, 09 Nov 2010 06:54:02 +0000

I agree with the other people on the first two questions. But I’m sorry but why is the answer for the last question B? Carbon Dioxide reacts with Carbon at high temperatures to form Carbon Monoxide in the chemical reaction CO2(g)+C(s)=2CO(g) so Carbon dioxide causes the Carbon atom to change from an oxidation state of 0 to 2+ so it has been oxidised and Carbon Dioxide should be an oxidising agent. Carbon on the other hand reacts with Oxygen to form Carbon Dioxide so Oxygen changed from an oxidation state of 0 to 2- so it is reduced and Carbon should be a reducing agent. The answer should be C. Will someone please clarify?

By: khalid

khalid — Wed, 13 Jan 2010 14:33:52 +0000

well done !!!