Qualification > Sciences
CHEMISTRY PAPER 1 HERE
esso:
--- Quote from: madee on June 11, 2009, 10:03:50 am ---
--- Quote from: john12345 on June 10, 2009, 04:46:40 pm ---nd one more question
which process can convert molecules to a new substance by removing hydrogen atoms
A displacement
B fermentation
C neutralisation
D oxidation
how do you solve this question
--- End quote ---
john it is oxidation By the way it is not der 4r us it cums in O-levels loss of hydrogen is oxidation
--- End quote ---
from which paper is this question ???
aquarian93:
--- Quote from: i-insane on June 11, 2009, 02:53:11 pm ---
--- Quote from: aquarian93 on June 11, 2009, 02:49:20 pm ---
--- Quote from: i-insane on June 11, 2009, 02:44:24 pm ---
--- Quote from: aquarian93 on June 11, 2009, 02:42:13 pm ---this is from may 05, if anyone has solved it, pls help me.
for question 16, the answer is D
y cnt it b C? pls help, thanks in advance
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For 3, there would be no loss in mass, as any gas produced would remain inside the conical flask, and not be able to excape through the stopper.
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yea bt if it dusnt escape, u can still use it cuz the mass will increase as gas is produced and wont escape. da mass will increase
rite?
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Umm no, conservation of mass = mass of products is always equal to mass of reactants. So, to show the rate of reaction, a decrease in mass must occur.
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ok so always a decrease in mass.
thanks alot :) +rep
aquarian93:
and guys doesnt sodium oxide hav a pH above 7 (metal oxide)
den how cum the answer in nov 05, question 17 is C ???
girl_92:
--- Quote from: aquarian93 on June 11, 2009, 02:57:39 pm ---and guys doesnt sodium oxide hav a pH above 7 (metal oxide)
den how cum the answer in nov 05, question 17 is C ???
--- End quote ---
it bcums dilute pH is lowered
nid404:
--- Quote from: aquarian93 on June 11, 2009, 02:57:39 pm ---and guys doesnt sodium oxide hav a pH above 7 (metal oxide)
den how cum the answer in nov 05, question 17 is C ???
--- End quote ---
Read the question correctly. Sodium oxide, when in solution it forms OH-ions which give the pH for the solution and changes pH of water(7) to 12
Hence C
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