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chemistry 1c

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can anyone please recommend me a good webstie to revise calculations?
i kinda struggled with calculations specially with the tonnes thingy !
thanks.
 
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1.36 draw a simple diagram to represent the positions of the ions in a crystal of sodium
chloride.

I found this in the specification, the content in bold that is assessed in paper 2..
It is like, really SHOCKING, how can we do that impossible diagram?
 
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Yeah it is, I DON'T KNOW HOW TO DO THIS, I'm studying chemistry not Level 1 Art
It's easy just draw a cuboid and draw empty large balls at the vertices and in the middle and black small balls between each two large balls and and just join them :)
 
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ELECTROLYSIS CALCULATION!!!
SOMEONE PLEASE EXPLAIN ELECTROLYSIS CALCULATION..
Electrolysis calculations depends on Faraday and also the reaction occurs in both electrodes
First electrode let it be : Na ---> Na+2 + 2e-
second electrode let it be : Cl- + e- ----> Cl

Now the question is the electricity passed in the first electrode is 2 Faraday for example now he wants the mass sodium or the number of moles
just do it easily by the ratio between the electrons which represents electricity 1 : 2 and the number of moles of the electrons is the 2 Faraday
then 2/2 = 1 mole that's the no. of moles of Sodium and also If you want to get the mass multiply by the molar mass which is 23 for the sodium (quiet easy)
Now for the partially hardest place (but I think all the electrolysis calculations are baby games). OK then you must now know that the 1 faraday = 96000 coloumb
so you must know that coloumb / time = ampere, Coloumb = time * ampere (very easy ain't it). Hope I helped you Good luck
 
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59
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1.36 draw a simple diagram to represent the positions of the ions in a crystal of sodium
chloride.

I found this in the specification, the content in bold that is assessed in paper 2..
It is like, really SHOCKING, how can we do that impossible diagram?
I should draw it on a paper but I will try to assemble this for you, first you should draw a simple cube with the three dimensions. I mean you must show the line at the back. so you will first draw a big molecules of Chlorine on all the vertex points then draw at the middle of each line a small sodium molecule to make sure you did make sure that each Chlorine molecule connected with 3 sodium molecules (I think its good right now). Now you must draw line on the middle of each square I mean connect all the sodium molecules with each others and in every intersection in each square. draw a Chlorine molecule and you finished. just try to draw it many times as I told you believe me you will draw it in the exam in just 1 or 2 minutes
 
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Electrolysis calculations depends on Faraday and also the reaction occurs in both electrodes
First electrode let it be : Na ---> Na+2 + 2e-
second electrode let it be : Cl- + e- ----> Cl

Now the question is the electricity passed in the first electrode is 2 Faraday for example now he wants the mass sodium or the number of moles
just do it easily by the ratio between the electrons which represents electricity 1 : 2 and the number of moles of the electrons is the 2 Faraday
then 2/2 = 1 mole that's the no. of moles of Sodium and also If you want to get the mass multiply by the molar mass which is 23 for the sodium (quiet easy)
Now for the partially hardest place (but I think all the electrolysis calculations are baby games). OK then you must now know that the 1 faraday = 96000 coloumb
so you must know that coloumb / time = ampere, Coloumb = time * ampere (very easy ain't it). Hope I helped you Good luck
that's wrong!
it 's Na+e--->Na
and 2CL- - 2E --->CL2
!!!
 
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