Qualification > Sciences
CHEMISTRY PAPER 1 HERE
amy.mym:
Ohhhhh yeah yeah thats the thing about the cations ans anions sheet that we had to learn
Thanks man appreciated
REP+ for u :D
amy.mym:
hey sorry a few questions as well
In Nov 2000 Question 23
Why is it B ?
And June 2003 Question 16
No idea why its C
But is it because Copper II when in solution is blue ?
kam:
--- Quote from: amy.mym on June 12, 2009, 03:03:11 am ---hey sorry a few questions as well
In Nov 2000 Question 23
Why is it B ?
And June 2003 Question 16
No idea why its C
But is it because Copper II when in solution is blue ?
--- End quote ---
what has colour to do with it?
i really dont know why they use co2 instead of co sorry
i dont have nov 2000 dunno the question sorry bout tht too
thx amy + rep 2 u 2 ;D
angell:
Nov 2000
B because in a displacement reaction, a more reactive element displaces the less reactive one, therefore, CHLORINE is more reactive than BROMINE, and displaces it, hence BR2 is formed, which turns the solution brown!
Read up displacement reactions in ''The Periodic Table''
and for m/j 03
it is white to blue because it is 'hydrated'. it i s a copper sulphate salt, reversible reaction, when u add water it goes from white to blue. when u heat it, water is taken away, so blue to white!
kam:
sorry amy i had the wrong paper
yes it is at first hydrated(with water) then dehydrates
notice they r asking about the products not reactants
white toblue cuz when heated it turns white
then if u add water it turns blue
heat energy is taken out bcuz when u turn hydrated copper 2 sulphate its exothermic
but when opposite its endo
@angelll, u r right too
i just wnted to explain the energy part as well
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