Biology; Chemistry; Physics: Post your doubts here!

[MustafaMotani]

i double checked the ms ryt now
there are 2 equations for this reaction in it:
2H2O - 2e- --> 2H+ + O2
and the other one is:
2H2O --> 2H+ + O2 + 2e-

again in both the equations the H is not balancing out...!! :/

both are same

 

[Dukeofwin]

3

Thanks!

 

[MustafaMotani]

Spidey21 and MustafaMotani Thanks, both are spot on!

 

[Spidey21]

Thanks!

np...

 

[Dukeofwin]

don't know about the first question exactly but for the second question is it simple cell or electrolytic?? if simple then the more reactive will b the anode (Zinc). is that ryt?

well spidey and mustafamotani were right on the money!

 

[Spidey21]

well spidey and mustafamotani were right on the money!

so wheres my money??

 

[xxvvyy]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Chemistry (5070)/5070_w05_qp_2.pdf

question no 5/ a/ ii)

please help guyz

 

[Spidey21]

daredevil did you understand the equation of the photosynthesis question??

 

[Dukeofwin]

Think time people!
Explain why all cell reactions are exhothermic and redox?(2)

If a solution contains dilute sulphuric acid and It has one ELECTRODE as Iron and Other ELECTRODE as Zinc! and Hydrogen gas evolves at Iron Electrode what would be the Anode? Give a reason for your choice(2)

Please write an overall reaction occuring in the cell!

 

[MustafaMotani]

http://www.xtremepapers.com/papers/CIE/Cambridge International O Level/Chemistry (5070)/5070_w05_qp_2.pdf

question no 5/ a/ ii)

0.45 dm3

 

[Dukeofwin]

so wheres my money??

ON the MONEY mate!

 

[MustafaMotani]

so wheres my money??

do u kept him to give money.. he is miser ..

 

[Spidey21]

please help guyz

0.083 mol?
you can take out the volume by Mol=Vol/24dm3

 

[xxvvyy]

0.45 dm3

the marking scheme says 0.9 dm^3 ?

 

[Dukeofwin]

Overall reaction please?

 

[MustafaMotani]

the marking scheme says 0.9 dm^3 ?

then i must have divided it by 2 for no reason... my oncentration is diverted ..

 

[syed1995]

Name the elements needed in the fertilizers and what benefit do they bring to the plants ...!

 

[xxvvyy]

then i must have divided it by 2 for no reason... my oncentration is diverted ..

we have to right, the ratio of moles is 2:1?

 

[syed1995]

then i must have divided it by 2 for no reason... my oncentration is diverted ..

Or maybe the marking scheme is wrong again =D

 

[Spidey21]

Name the elements needed in the fertilizers and what benefit do they bring to the plants ...!

Nitrates : help in plant growth and reformation of torn parts of the cells
Magnesium : Important part of chlorophyll
Potassium : Dont remember
bio ke yaad dila de yar
LOL!