Edexcel chemistry - unit 2 19th january 2012

OP

I'll post a few questions & lot can answer them...
I'll post after my revision :smile:

Hopefully by night xx

Reply 101

cisne

6

Original post by aqua05

I'll post a few questions & lot can answer them...
I'll post after my revision :smile:

Hopefully by night xx

I have some notes to post too....but there's a lot of stuff to type thats why I took pictures of it..I was wondering whether its allowed or not?? I mean uploading pictures from the revision guide ...???

Reply 102

Original post by aqua05

I'll post a few questions & lot can answer them...
I'll post after my revision :smile:

Hopefully by night xx

Original post by arnab

i prefer this unit a lot more then unit1...its more logical and u goota know ur **** for to answer the questions right lol

Original post by cisne

I have some notes to post too....but there's a lot of stuff to type thats why I took pictures of it..I was wondering whether its allowed or not?? I mean uploading pictures from the revision guide ...???

brap brap brappp

give two observations you would make when an alcohol reacts with sodium metal

Reply 103

OP

Original post by James A

brap brap brappp

give two observations you would make when an alcohol reacts with sodium metal

effervescence of H2 gas
sodium sinks
test tube becomes hot :smile:

Reply 104

OP

Original post by cisne

I have some notes to post too....but there's a lot of stuff to type thats why I took pictures of it..I was wondering whether its allowed or not?? I mean uploading pictures from the revision guide ...???

i really dont know :frown:

its better not to put pictures from the revision guide as it is copy righted... how about you telling us which revision guide you using & the page numbers.. ?
I have the chemistry salters revision guide, george facer text book & the blue book

Reply 105

Original post by aqua05

effervescence of H2 gas
sodium sinks
test tube becomes hot :smile:

effervescense of h2 gas is incorrect im afraid. if you do put that down, they want to know how you came to conclusion that hydrogen is the gas given off. therefore you need to say effervescense of colourless gas

test tube becomes hot is perfectly correct.

however sodium sinks? its better to say sodium dissolves/dissappear

Reply 106

OP

Original post by James A

effervescense of h2 gas is incorrect im afraid. if you do put that down, they want to know how you came to conclusion that hydrogen is the gas given off. therefore you need to say effervescense of colourless gas

test tube becomes hot is perfectly correct.

however sodium sinks? its better to say sodium dissolves/dissappear

thanks ! i'll take a note of that :biggrin:

Reply 107

OP

my question to everyone

why does carbon dioxide & methane absorb infrared radiation even though the molecule is non polar ?

Reply 108

cisne

6

Original post by aqua05

i really dont know :frown:

its better not to put pictures from the revision guide as it is copy righted... how about you telling us which revision guide you using & the page numbers.. ?
I have the chemistry salters revision guide, george facer text book & the blue book

I think that book is avaiable only in Maldives and in India,...
ok,its better not to upload,thanks

Reply 109

Original post by aqua05

my question to everyone

why does carbon dioxide & methane absorb infrared radiation even though the molecule is non polar ?

because their dipole moments change when they vibrate?

Reply 110

OP

can anyone post notes on group 7 & group 2 metals ??! just realised im not good in that :frown:

Reply 111

Cetacea

8

Original post by James A

so propanal is an aldehyde, therefore NO HYDROGEN BONDS OCCUR, however PERMANENT DIPOLE DIPOLE interactions OCCUR and of course LONDON FORCES OCCURS IN ALL MOLECULES MOLECULES

Correct!

Reply 112

OP

Original post by James A

because their dipole moments change when they vibrate?

Yes the molecule vibrates in 3 ways - asymmetric streching, symmetric stretching and bending.
Symmetric stretching doesnot cause any change in dipoles thus doesnot absorb IR, where as the other 2 modes cause a change in dipoles so absorbs IR :smile:

(edited 12 years ago)

Reply 113

BeHappy

Original post by James A

however sodium sinks? its better to say sodium dissolves/dissappear

A white solid is produced gets you the mark. Every time. [The white solid being sodium ethoxide/butoxide e.t.c.]

Reply 114

Original post by Amy7

A white solid is produced gets you the mark. Every time. [The white solid being sodium ethoxide/butoxide e.t.c.]

Reply 115

OP

Can anyone explain to me the meaning of bond length ?? :s-smilie:

It is in the shapes of molecules & ions..
thanks :smile:

Reply 116

OP

Original post by Amy7

A white solid is produced gets you the mark. Every time. [The white solid being sodium ethoxide/butoxide e.t.c.]

Great observation :biggrin:

I wouldnt have thought about it !!

Reply 117

OP

and i need help
can anyone explain to me the structure of a carbon nanotube ??

Thanks :smile:

Reply 118

OP