Qualification > Sciences
CHEMISTRY PAPER 1 HERE
Priceless:
ok itz defi sodium 4 da 1st
but guyz 4 da 2nd...itz 'b'.....itz using copper electrodes wich r active electrodes.......im sure u hv don't da purification of copper using electrolysis...itz da same thng
n 3rd.....im not sure but i thnk itz sodium bcuz itz an alkali wich forms white compounds....
plz nid or any1...correct me if im wrong.....thnku :)
MR.BooMBastiC:
--- Quote from: Priceless on June 11, 2009, 10:34:02 am ---ok itz defi sodium 4 da 1st
but guyz 4 da 2nd...itz 'b'.....itz using copper electrodes wich r active electrodes.......im sure u hv don't da purification of copper using electrolysis...itz da same thng
n 3rd.....im not sure but i thnk itz sodium bcuz itz an alkali wich forms white compounds....
plz nid or any1...correct me if im wrong.....thnku :)
--- End quote ---
yeah....priceless
thats wat i said...2 is b
cuz cu electrodes r being used!!!!
....:
--- Quote from: cockyxrocker on June 11, 2009, 10:16:23 am ---OK so I have a few questions
1)hydrogen can form both ionic and covalent compounds
with which element will hydorgen form an ionic compound?
a-carbon
b-chlorine
c-nitrogen
d-sodium
2)CuSO4 (aq) is electrolysed using Cu electrodes
what observations will be made?
at anode at cathode electrolyte
a- anode dissolves pink solid forms blue color fades
b- anode dissolves pink solid forms no change
c- colourless gas forms colourless gas forms no change
d- colourless gas forms pink solid forms blue color fades
3) The carbonate of metal x is a white solid
it decomposes when heated to form co2 gas and a yellow solid oxide
what is metal x
a-copper
b-iron
c-lead
d-sodium
Can somebody please answer them with explaination
Thanks
--- End quote ---
Last one has to be iron.
Copper oxide is black.
Sodium carbonate doesn't decompose.
Iron oxide is yellow.
Lead oxide is dark brown-black
girl_92:
--- Quote from: Priceless on June 11, 2009, 10:34:02 am ---ok itz defi sodium 4 da 1st
but guyz 4 da 2nd...itz 'b'.....itz using copper electrodes wich r active electrodes.......im sure u hv don't da purification of copper using electrolysis...itz da same thng
n 3rd.....im not sure but i thnk itz sodium bcuz itz an alkali wich forms white compounds....
plz nid or any1...correct me if im wrong.....thnku :)
--- End quote ---
IT CANT BE B for da second one because the overall concentration of cu2+ ions remain the saME its jus the copper frm the anode tht gets coated on the cathode
n abt 3 it culd be copper
it cannot be sodium because carbonates of highly reactive metals are quite stable n do not decompose on heating except lithium i think n copper oxide i think is yellow sort of
plz correct me if im wrong
girl_92:
yea srry copper oxide is black
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