Qualification > Sciences
CHEMISTRY PAPER 1 HERE
girl_92:
--- Quote from: winnie101 on June 11, 2009, 12:44:02 pm ---hi
does anyi know why the ans to q29, 2004jun is C
--- End quote ---
take the percentage of o2 to be 21% now
21/100*x=30
solve u will get 142 sumthin so the nearest value is 150 so it is c
Clem:
--- Quote from: Triple_A on June 11, 2009, 12:37:31 pm ---
--- Quote from: madee on June 11, 2009, 12:33:32 pm ---
--- Quote from: Clem on June 11, 2009, 12:26:30 pm ---Hey! Can someone tell me why q4 in november 08 is A? Ionic compounds are soluble in ethanol and water
And also november 2007 no. 21, shouldn' it form a blue percepitate??
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ionic compounds dissolve in water n covalent dont n covalent dissolve in organic solvents n ionic dont so with either methods dey can be separated the undissolved compound is left as reidue
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reagent aq BaCl is wrong
@mizuki........polyethene
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Thanks! XD
Why is it wrong? It will form a blue percepitate of copper chloride right?
247sports:
--- Quote from: sweetest angel on June 11, 2009, 12:32:47 pm ---
--- Quote from: esso on June 11, 2009, 12:23:13 pm ---i need help in this question <
Three reactions used in the manufacture of sulphuric acid are shown.
1 S + O2 ? SO2
2 2SO2 + O2 ? 2SO3
3 SO3 + H2O ? H2SO4
Which of these reactions are redox reactions?
A 1 only
B 3 only
C 1 and 2 only
D 2 and 3 only
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2 and 3?
i saw this question be4...can u tell me which year please?
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may/june 2007 :)
girl_92:
--- Quote from: cool_dude on June 11, 2009, 12:53:57 pm ---u guys..
help me..
ppr 1,june04, 32..
why would the screws be the aluminium?..
aluminium would never corrode..because it forms oxide layer?
--- End quote ---
here dey r testing for preferential discharge thing aluminium is more reactive hence it will loose electrons n will not let steel to do so
cool_dude:
--- Quote from: madee on June 11, 2009, 01:07:49 pm ---
--- Quote from: cool_dude on June 11, 2009, 12:53:57 pm ---u guys..
help me..
ppr 1,june04, 32..
why would the screws be the aluminium?..
aluminium would never corrode..because it forms oxide layer?
--- End quote ---
here dey r testing for preferential discharge thing aluminium is more reactive hence it will loose electrons n will not let steel to do so
--- End quote ---
oh...really?..
i alwys keep rembr that aluminium doesn't corrode..
nways..thanks..+rep
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