Qualification > Sciences
CHEMISTRY PAPER 1 HERE
Bani:
--- Quote from: nid404 on June 11, 2009, 06:16:31 pm ---
--- Quote from: Bani on June 11, 2009, 06:00:38 pm ---
--- Quote from: sweetest angel on June 11, 2009, 05:51:43 pm ---
--- Quote from: Bani on June 11, 2009, 05:47:16 pm ---thanks a lot everyone!
someone please try answering my previous question (M/J 2007, Q16-----the one about redox reaction) Why is the answer C?
--- End quote ---
since in equation 3 no reactants have lost or gained electrons, oxygen or hydrogen!
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Ya,but why is equation 1 and 2 REDOX?
1 and 2 are only oxidation, not reduction...
please help...
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it's a little difficult to explain
but i'll try...in the first one Sulphur gains oxygen atoms(oxidation) but oxygen gains electrons(reduction).
in the second one sulphur gains oxygen but oxygen gains electrons
whereas in third one although oxygen is gained, there is no transfer of electrons and hydrogen does not lose oxygen but combines with SO4
It's very difficult to explain.
* Oxygen's oxidation state reduces in the covalent bond it forms with sulphur
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Thanks a lot!!!
+rep for you :D
sweetsh:
--- Quote from: simba on June 11, 2009, 06:47:38 pm ---in question 38 june 08......
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C (petroleum)
Petrol:
Can u please tell me whats the answer for May/June 2008 Question 19
Mark scheme says D.. i think its C
Cause 2KOH --> H20 thats ph going from 14 - 7 so decreases :s why is it d in the ms its wrong rite?
nid404:
--- Quote from: Petrol on June 11, 2009, 06:59:39 pm ---Can u please tell me whats the answer for May/June 2008 Question 19
Mark scheme says D.. i think its C
Cause 2KOH --> H20 thats ph going from 14 - 7 so decreases :s why is it d in the ms its wrong rite?
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There is excess KOH
pH of water increases from 7 to 13/14
Petrol:
can u explain further ... and please are u 100%?
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