Chemistry: Post your doubts here!

[Jinkglex]

Im pretty sure the majority of xtreme speaks urdu.

And I believe for chirality or isomeric compounds the examiner says ANY may be accepted, as long as they are reasonably possible to make or exist at all.

 

[knowitall10]

Question guys..

C4H8O2 contains C=C and OH ... Two types of steroisomerism exist for this compound... Draw the displayed formula of both pairs of isomers ( 4 compounds )

One is cis-trans...
This is the marking scheme's answer

This is my answer: ( i was too lazy to draw the trans in paint... )

Now my question, is the marking scheme answer the only answer they accept, because that would be just unfair

Something sbout your diagram doesnt seem to be right... Can someone help me with what's wrong in his diagram? I would draw the mark scheme answer.. nothing else would really occur to me...

 

[Alice123]

Theres also nuecleophilic substitution.

And Alice:

All period 3 elements react with Oxygen [except argon, ofcourse]

They form oxides and burn with varying flame colors [White for MG/AL, blue for sulphur, yellow for phosphorous etc] The oxide formula depends on their valency and some exist as different oxides [e.g SO2, SO3].

They form chlorides [except Chlorine, ofcourse, and argon] as well, but these usually have a constant formulae.

They will ALWAYS BE POSITIVE OXIDATION NUMBER as they react with elements MORE ELECTRONEGATIVE THEN THEMSELF.

For example Na gives Na+ usually, makes Na2O
Mg gives Mg2+, gives MgO

Couldnt really find anything besides these....unless you meant reactions with water which are more towards RATTA then conceptual learning

THANKS.....Does Be react with water or oxygen??? Jinkglex its nt written in my book......

 

[knowitall10]

Question guys..

C4H8O2 contains C=C and OH ... Two types of steroisomerism exist for this compound... Draw the displayed formula of both pairs of isomers ( 4 compounds )

One is cis-trans...
This is the marking scheme's answer

This is my answer: ( i was too lazy to draw the trans in paint... )

Now my question, is the marking scheme answer the only answer they accept, because that would be just unfair

Wait... i think yours will be accepted. It's exactly the same thing.. don't you think?

 

[PANDA-]

Im pretty sure the majority of xtreme speaks urdu.

And I believe for chirality or isomeric compounds the examiner says ANY may be accepted, as long as they are reasonably possible to make or exist at all.

They didn't say accept any
and it's a diol btw, what I drew. Oh and I googled it, and found it
http://www.chemspider.com/Chemical-Structure.4528353.html

 

[Jinkglex]

Be isnt a part of period 3 but as far as my opinion goes, i believe it would not react with oxygen or H20 as reactivity decreases going up group 2, and since Mg already has such a slow reaction, then the chances of Be reacting are minimal!

Btw, if i helped anyone here, i do request that you please do remember me in your prayers IA =)

 

[PANDA-]

Wait... i think yours will be accepted. It's exactly the same thing.. don't you think?

Close, but not the same...
Mine is 2 butene 2-3 diol...
The marking scheme is 2 butene 1-4 diol

 

[knowitall10]

so

They didn't say accept any
and it's a diol btw, what I drew. Oh and I googled it, and found it
http://www.chemspider.com/Chemical-Structure.4528353.html

yours is right
Mabrook!

 

[Jinkglex]

Panda, did the marking scheme or question ever suggest the PLACEMENT of the OH being specific??

 

[knowitall10]

Close, but not the same...
Mine is 2 butene 2-3 diol...
The marking scheme is 2 butene 1-4 diol

Plus, you dont have to be mark scheme specific now do u? it's made for teachers... probably yours will be accepted cuz there's ABSOLUTELY nothing wrong with it.

 

[Alice123]

Be isnt a part of period 3 but as far as my opinion goes, i believe it would not react with oxygen or H20 as reactivity decreases going up group 2, and since Mg already has such a slow reaction, then the chances of Be reacting are minimal!

Btw, if i helped anyone here, i do request that you please do remember me in your prayers IA =)

its really annoying...,. im forgettting evrything b4 the exam ....... I'lll pray for u for sure....Hope u get the best grades!!!!!

 

[knowitall10]

there's no capacity or size of a U tube is there?

 

[PANDA-]

Panda, did the marking scheme or question ever suggest the PLACEMENT of the OH being specific??

Well no, but I just want to know, are answers that are not in the marking scheme but satisfy the question correct, or must the be like the mark scheme... If they must be like the marking scheme, I'd be doomed

 

[MaxStudentALevel]

Just a side question: does almost everyone know urdu here??

Just a side question: does almost everyone know urdu here??

Yep! I'm pretty sure this website started here originally or something along those lines!

 

[knowitall10]

Well no, but I just want to know, are answers that are not in the marking scheme but satisfy the question correct, or must the be like the mark scheme... If they must be like the marking scheme, I'd be doomed

U worry too much..

 

[knowitall10]

Yep! I'm pretty sure this website started here originally or something along those lines!

i could guess

 

[Manobilly]

I want to know how we calculate the kc like in questions may/June 2007 question. 2c

 

[MaxStudentALevel]

Something sbout your diagram doesnt seem to be right... Can someone help me with what's wrong in his diagram? I would draw the mark scheme answer.. nothing else would really occur to me...

EXACTLY!! I thinkit has something to do with the groups attached but I'd draw the MS also.
Then again I can't pinpoint an error in his...

 

[knowitall10]

I want to know how we calculate the kc like in questions may/June 2007 question. 2c

Which paper are you talkin abt?

 

[Manobilly]

Which paper are you talkin abt?

Paper 2 !sorry