iGCSE 2012 Chemistry Discussion
Chemistry exam discussion - share revision tips in preparation for GCSE, A Level and other chemistry exams and discuss how they went afterwards.
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Graphite is giant covalent... There is one delocalised electron, hence the conductivity and the lubrication; te attraction between layers is lowered as a result of this. It's not 2d... And I'm not sure if it contains intermolecular forces(Original post by ▀▀▒=(◕ ‿ ◕)=▒r▀▀)
Graphite is a giant covalent structure and is an allotrope of carbon. Unlike diamond it if formed in 2D layers and does contain weak intermolecular forces. But as it is a giant covalent structure to sublime it you not only need to bread the weak intermolecular forces but the covalent bonds as well..
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Re: iGCSE 2012 Chemistry DiscussionYou're wrong. Don't confuse people...little knowledge is dangerous...(Original post by Sub150)
Graphite is giant covalent... There is one delocalised electron, hence the conductivity and the lubrication; te attraction between layers is lowered as a result of this. It's not 2d... And I'm not sure if it contains intermolecular forces
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1. It's lubrication is not a direct nor an indirect result of it having delocalised electrons.
2.It is a giant molecule that continues in 2D ie it layers are on one plane
3.It does contain intermolecular forces. Then what do you call the weaf forces between the layers? Van-de-wall forces? van-de-wall forces are also a type of intermolecular attractions! -
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Re: iGCSE 2012 Chemistry DiscussionHeey what's up with the calculations about Moles and Faradays/charge/electrons? And I don't understand electrolysis moles calculations...
In fact I don't understand electrolysis at all...
So how does that work?
Does anyone know?
I don't get ionic equations....
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Re: iGCSE 2012 Chemistry DiscussionAbsolutely right(Original post by ▀▀▒=(◕ ‿ ◕)=▒r▀▀)
You're wrong. Don't confuse people...little knowledge is dangerous...
1. It's lubrication is not a direct nor an indirect result of it having delocalised electrons.
2.It is a giant molecule that continues in 2D ie it layers are on one plane
3.It does contain intermolecular forces. Then what do you call the weaf forces between the layers? Van-de-wall forces? van-de-wall forces are also a type of intermolecular attractions! -
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Re: iGCSE 2012 Chemistry DiscussionWhat I meant was that there are NO intermolecular forces of attraction between molecules in graphite of the same layer. There are weak forces of attraction between the layers, hence its slippery property. But when you vaguely say that the inter molecular forces of attraction are weak, you can assume that intermolecular forces of attraction between molecules of the same layer are being talked about... -
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Re: iGCSE 2012 Chemistry DiscussionIt is an indirect result of the graphite having delocalized an electron per C atom, as it therefore does not form the 4 C-C bonds which are present in diamond, which is why there are merely intermolecular forces between the layers.(Original post by ▀▀▒=(◕ ‿ ◕)=▒r▀▀)
You're wrong. Don't confuse people...little knowledge is dangerous...
1. It's lubrication is not a direct nor an indirect result of it having delocalised electrons.
2.It is a giant molecule that continues in 2D ie it layers are on one plane
3.It does contain intermolecular forces. Then what do you call the weaf forces between the layers? Van-de-wall forces? van-de-wall forces are also a type of intermolecular attractions!
That's still misleading - atoms themselves are not 2D. Why not just say that graphite consists of layers?
Van der Waals forces are all intermolecular forces of attraction. But graphite cannot melt or evaporate into different layers simply through the breaking of its van der Waals forces; you'd also need to break the (much stronger) C-C covalent bonds within each layer, which requires a lot more energy. -
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Re: iGCSE 2012 Chemistry DiscussionThats what i posted in the previous page!(Original post by Big-Daddy)
That's still misleading - atoms themselves are not 2D. Why not just say that graphite consists of layers?
Van der Waals forces are all intermolecular forces of attraction. But graphite cannot melt or evaporate into different layers simply through the breaking of its van der Waals forces; you'd also need to break the (much stronger) C-C covalent bonds within each layer, which requires a lot more energy.
Um mm, yes you're right about the inter-molecular forces occurring as a result of a lone electron.(Original post by ▀▀▒=(◕ ‿ ◕)=▒r▀▀)
Graphite is a giant covalent structure and is an allotrope of carbon. Unlike diamond it if formed in 2D layers and does contain weak intermolecular forces. But as it is a giant covalent structure to sublime it you not only need to bread the weak intermolecular forces but the covalent bonds as well.. -
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Re: iGCSE 2012 Chemistry DiscussionNo you didnt mean it. Read what you wrote below(Original post by Relaxedexams)
What I meant was that there are NO intermolecular forces of attraction between molecules in graphite of the same layer.
But NOW you mean IT(Original post by Relaxedexams)
There arent intermolecular attractions in graphite. Graphite is a giant covalant substance. It doesn't have intermolecular forces.
(Original post by Relaxedexams)
There are weak forces of attraction between the layers, hence its slippery property.What did you mean when you wrote the earlier post? Your's was the most vaguest , almost confusing me (thats why i am replying)(Original post by Relaxedexams;37797396. But [B)
when you vaguely say[/B] that the inter molecular forces of attraction are weak, you can assume that intermolecular forces of attraction between molecules of the same layer are being talked about... -
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Re: iGCSE 2012 Chemistry DiscussionWhat I meant when I wrote the earlier post was that graphite has no intermolecular forces of attraction, like in a simple molecular substance like water for example. That is why I stated that graphite is a giant covalent substance and also asked if the forces between layers were being talked about.(Original post by ▀▀▒=(◕ ‿ ◕)=▒r▀▀)
No you didnt mean it. Read what you wrote below
But NOW you mean IT
What did you mean when you wrote the earlier post? Your's was the most vaguest , almost confusing me (thats why i am replying) -
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Number of mole = mass/RAM(Original post by NilFBosh)
can anyone tell me how to find the concentration in g/dm3...there's a question in the last part of hte ;ast question in jan 2012 paper 2...sumone help!
If you know moles and RAM find mass...
Conc = mols/vol
Use that mass value instead of mols
HOWEVER- THEY WILL NEVER ASK I DON'T THINK FOR A RESULT IN G/dm3 - only mols/dm3
Check If you have read the question wrong!
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Re: iGCSE 2012 Chemistry Discussiongoodluck to u too!! we sail in da same boat!!(Original post by harrietx123x)
i'm terrible at chemistry! good luck everybody in the last exam tomorrow x
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Re: iGCSE 2012 Chemistry DiscussionIt was precipitate, no precipitate and precipitate.(Original post by NilFBosh)
doez anyone know tha answers for that question where a table came and we had to write the precipates.the question came for our paper -
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Re: iGCSE 2012 Chemistry DiscussionI believe calcium and barium made precipitates and potassium no precipitate?(Original post by Relaxedexams)
It was precipitate, no precipitate and precipitate. -
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Re: iGCSE 2012 Chemistry Discussionthats great..thats what i got but what was what? i think i got sumthing like dis(Original post by Relaxedexams)
It was precipitate, no precipitate and precipitate.
precipate of....
no precipitate
precipitate of...
