Chemistry: Post your doubts here!

[kitkat <3 :P]

An easy, albeit time consuming way to figure these questions out is to simply draw the isomers. You know there's a double bond, so it must show geometric isomerism - cis and trans, that makes 2. But they aren't asking for just geometric isomers, they're asking for all the isomers. Another one would be but-1-ene. So that makes 3. I know this isn't the best way to work it out, but it's better than nothing.

but there is a differenc betweeen structural and stereo isomers isnt it :/?

 

[MaboroshI_I]

but there is a differenc betweeen structural and stereo isomers isnt it :/?

The question says 'structural or otherwise' :S I don't know, I could be wrong.

Could you or someone else help me with the questions I posted earlier? Just on the previous page.

 

[kitkat <3 :P]

The question says 'structural or otherwise' :S I don't know, I could be wrong.

Could you or someone else help me with the questions I posted earlier? Just on the previous page.

well i think the cis and tra wont be included in this one :/

i'll try

 

[Lujain M.]

hey can someone help me with q9 june 2012 p.11? thanks in advance

 

[Ahmed Aqdam]

I thought more the lone pairs more the replution and hence more the angle
Q20 i am confused about A and B??

More repulsion when more lone pairs so the bonding pairs are pushed closer together and hence less angle.

20: The cis isomer is the one in which the two H are on the same side of the C-C double bond.
The one in B is trans as H is on different side.

 

[GCE As and a level]

WHO HATES CHEMISTRY??

 

[_Ahmad]

Could someone please help me with a few questions from this paper? http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
Qs 13, 19, 27, 29 and 34.

I'm sorry if these questions are being repeated. Thank you to anyone who can help me with these!

Q13
5HIO---->2I2 + HIO3 + 2H2O
answer =B
Q19
check this website
http://www.chemguide.co.uk/inorganic/group7/halideions.html

 

[princessnoor]

More repulsion when more lone pairs so the bonding pairs are pushed closer together and hence less angle.

20: The cis isomer is the one in which the two H are on the same side of the C-C double bond.
The one in B is trans as H is on different side.

hey i found u here too
can u help me with question 40 in this paper
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s13_qp_12.pdf

 

[kitkat <3 :P]

Q13
5HIO---->2I2 + HIO3 + 2H2O
answer =B
Q19
check this website
http://www.chemguide.co.uk/inorganic/group7/halideions.html

but markscheme says D

 

[_Ahmad]

but markscheme says D

Are you sure

 

[Hijab]

Can some one plz plz explain this question to me.... I would really be grateful

 

[_Ahmad]

Can some one plz plz explain this question to me.... I would really be grateful

Answer =D
beacuse C-I is a weakest bond (have lowest bond energy)

 

[Hijab]

Answer =D
beacuse C-I is a weakest bond (have lowest bond energy)

Thank you

 

[loveyuan]

An easy, albeit time consuming way to figure these questions out is to simply draw the isomers. You know there's a double bond, so it must show geometric isomerism - cis and trans, that makes 2. But they aren't asking for just geometric isomers, they're asking for all the isomers. Another one would be but-1-ene. So that makes 3. I know this isn't the best way to work it out, but it's better than nothing.

thanks a lot

 

[loveyuan]

Could someone please help me with a few questions from this paper? http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w10_qp_12.pdf
Qs 13, 19, 27, 29 and 34.

I'm sorry if these questions are being repeated. Thank you to anyone who can help me with these!

27 the above is COO bond so it is ester
once sulfuric acid added , the ester hydrolysis to acid and alkali
so the the answer will be a acid . then hydrogenation occur and all double bond gone.

29 NaCN is the catalyst for this reaction so D .

34 1 . sulfuric acid is strong acid so reaction will more vigorously than ch3cooh so temperature higher
2.yes because one more of sulfuric acid produce 2mol of H+ , so at first sulfuric acid will produce more than ch3cooh but at the end their amount of product will be the same.
3. their limiting reagent is acid and their number of the mole is same , so product will be the same too .

 

[Exo_luhan]

MJ 2008 Q15!!!some1 plz explain

 

[loveyuan]

MJ 2008 Q15!!!some1 plz explain

they were discussing the same question at previous page ya

 

[Exo_luhan]

MJ 2008 Q27!!!some1 plz explain

 

[Exo_luhan]

they were discussing the same question at previous page ya

i jus checkd 499 page but i didnt get

 

[Exo_luhan]

MJ 2008 Q21!!!some1 plz explain