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CHEMISTRY PAPER 1 HERE

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shafiq_92libra:
wat is an oxidation state??? i hhave no ide, i never paid attention in class when da teacher was teaching us ><, is it da same as valency??

kam:

--- Quote from: shafiq_92libra on June 12, 2009, 04:02:53 am ---wat is an oxidation state??? i hhave no ide, i never paid attention in class when da teacher was teaching us ><, is it da same as valency??

--- End quote ---

you can say tht yes

amy.mym:
thanks guys I owe u

REP+ for angell

shafiq_92libra:
thnnxx =D
and guys this question made no sense to me at all
ryt 2004 nov
question 11

11. A substance X is heated in an evaporating basin until there is no further change.
mass of basin and contents
before heating 25.52 g
after heating 26.63 g
What could X be?
A copper
B copper(II) carbonate
C copper(II) oxide
D hydrated copper(II) sulphate

da answer is a bt i hav no idea why

kam:

--- Quote from: shafiq_92libra on June 12, 2009, 04:15:39 am ---thnnxx =D
and guys this question made no sense to me at all
ryt 2004 nov
question 11

11. A substance X is heated in an evaporating basin until there is no further change.
mass of basin and contents
before heating 25.52 g
after heating 26.63 g
What could X be?
A copper
B copper(II) carbonate
C copper(II) oxide
D hydrated copper(II) sulphate

da answer is a bt i hav no idea why

--- End quote ---

luk, u heat the copper and forms copper 2 oxide
which is a black powder
so mass increases
it cant be the others cuz they all give out  either a gas or water or somat
gettit?

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