Chemistry: Post your doubts here!

[KurayamiKimmi]

plz answer,Q4

hey is your doubt solved?

 

[nerdybookworm]

hey is your doubt solved?

kimmii plz helpp me wd my doubtss

 

[Muhammad Asif]

Please answer questions 22, 24, and 34. Thank you very much.

http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_w09_qp_12.pdf

Q22=plymerise 1-2 dichloroethene and then hydrolise it all Cl will be replaced by OH giving the plymer shown......
Q24=the intermediate is a +charged carbocation which react with electrophile Br...thus accepts 2 electrons from it...so acceptor of pair of electrons is a electrophile.....
Q34=Sulphuric acid is not a product of a reaction of (NH4)2SO4+Ca(OH)2....thus answer is automatically C...still you need prove for Q34 i can do that

 

[nazzzzzz]

KMnO4 oxidises alcohols to aldehydes or ketones, and then rapidly oxidises the aldehyde to a carboxylic acid if you let it react.

Thanks so does that mean when KMnO4 oxidises alchohol to carboxylic acids and ketones respectively it is turned from orange to green? Therefore it gets reduced?

 

[Student12]

Thanks so does that mean when KMnO4 oxidises alchohol to carboxylic acids and ketones respectively it is turned from orange to green? Therefore it gets reduced?

it gets OXIDISED !

 

[hm12]

Someone please answer this.

is the answer D?

 

[Casablanca]

is the answer D?

No idea. I don't have the marking scheme. ._.

 

[Muhammad Asif]

Thanks so does that mean when KMnO4 oxidises alchohol to carboxylic acids and ketones respectively it is turned from orange to green? Therefore it gets reduced?

it gets OXIDISED !

the thing which is an oxidising agent always gets reduced it self..........................................

 

[Student12]

someone please answer my questions ?

 

[KurayamiKimmi]

kimmii plz helpp me wd my doubtss

i can try =) fire away !

 

[Casablanca]

is the answer D?

I thought it was 3.

 

[geek101]

hey is your doubt solved?

yes thank you

 

[KurayamiKimmi]

oh okay

 

[hm12]

No idea. I don't have the marking scheme. ._.

i dont know if i am right because i suck at these drawing and counting the numbers thingy questions but here is what i came up with

1)CH2=CHCH2CH2CH3
2)CH3CH=CHCH2CH3
3)H-C-(H)=(H)-C-CH2CH2CH3 i am trying to draw a cis isomer here i hope you get the structure
4)H-C-(H)=(CH2CH2CH3)-C-H the trans isomer
5)CH3-C-(H)=(H)-C-(CH2CH3) cis isomer
6)CH3-C-(H)=(CH2CH3)-C-H trans isomer

 

[Oliveme]

Q22=plymerise 1-2 dichloroethene and then hydrolise it all Cl will be replaced by OH giving the plymer shown......
Q24=the intermediate is a +charged carbocation which react with electrophile Br...thus accepts 2 electrons from it...so acceptor of pair of electrons is a electrophile.....
Q34=Sulphuric acid is not a product of a reaction of (NH4)2SO4+Ca(OH)2....thus answer is automatically C...still you need prove for Q34 i can do that

can you please elaborate? thank you.
and another question pls. explain in detail.
Question 7 http://www.xtremepapers.com/papers/... AS Level/Chemistry (9701)/9701_w10_qp_12.pdf

Thank you so very much

 

[Student12]

Flask X contains 5 dm3 of helium at 12 kPa pressure and flask Y contains 10 dm3 of neon at 6 kPa
pressure.
If the flasks are connected at constant temperature, what is the final pressure?
A 8 kPa B 9 kPa C 10 kPa D 11 kPa

Ans is A ??

 

[mushoo]

A monomer undergoes addition polymerization.A 1 mol sample of the monomer is completely polymerized.
How many moles of polymer might , theoretically, be formed?
1. 1
2. 10^-6
3. 1/ 6.02*10^23 (1/ Avogadro's cons.)



pls guys rep asap! :/ -_-

its from oct/nov 2009, ppr 12, ques 40!

 

[user]

Assalamoalaikum wr wb!

Since when is gaseous bromine purple...

This question is from N'10_12 Q 18

 

[Casablanca]

i dont know if i am right because i suck at these drawing and counting the numbers thingy questions but here is what i came up with

1)CH2=CHCH2CH2CH3
2)CH3CH=CHCH2CH3
3)H-C-(H)=(H)-C-CH2CH2CH3 i am trying to draw a cis isomer here i hope you get the structure
4)H-C-(H)=(CH2CH2CH3)-C-H the trans isomer
5)CH3-C-(H)=(H)-C-(CH2CH3) cis isomer
6)CH3-C-(H)=(CH2CH3)-C-H trans isomer

Ah, so there are 6? Thanks a lot, I appreciate the effort.

 

[Muhammad Asif]

A monomer undergoes addition polymerization.A 1 mol sample of the monomer is completely polymerized.
How many moles of polymer might , theoretically, be formed?
1. 1
2. 10^-6
3. 1/ 6.02*10^23 (1/ Avogadro's cons.)



pls guys rep asap! :/ -_-

its from oct/nov 2009, ppr 12, ques 40!

the number of moles polymers therotically can never be equal to the number of moles of monomer.....so 1 is not the answer thus only option is C