Chemistry paper 42 may/june 11

[boy2011]

B polymer that we have to made it was an addition polymer \..rytttttt????nd after hydrolysis waht was the other strutctre we have to made from formula C2H4O???nd wat was da strucure after ths part in which it was said that Structure C dont declourises bromine but react with iodine i thnk???wat was that i have drwan an aldehyde because with c2h4o only aldehyde was possible.....

Sum1 ans ths plx

 

[beacon_of_light]

@beacon. Yes it is but it supposed to be OH in the terminal end. OHCH(C2H5)COOH.
1. Extract dna
2. Using PCR
3. Restriciton enzyme
4. Put in agragose gel
5. Carry out electrophoresis
6. Forgot. Lol.

yeah I wrote the same monomer...
and 6 was label with radioactive phosphorus sumthing..

 

[beacon_of_light]

B polymer that we have to made it was an addition polymer \..rytttttt????nd after hydrolysis waht was the other strutctre we have to made from formula C2H4O???nd wat was da strucure after ths part in which it was said that Structure C dont declourises bromine but react with iodine i thnk???wat was that i have drwan an aldehyde because with c2h4o only aldehyde was possible.....

Sum1 ans ths plx

ya an addition polymer... CH(OH)--CH3 if I am not wrong
And then the correct structure was CH2(OH)CH3 ...becuz this structure shows positive result with I2(aq) and NaOH(aq) as stated in the qstn

 

[beacon_of_light]

My answe is from 0.1 nm to 10 nm. But on wiki it is said from 0.1 to 100. How was yours ?

So overall, what would be the GT for this paper ? I thought it is 60.

yeah i marked the same... 10^-8 to 10^-10

 

[Xenon]

@beacon. Yes it is but it supposed to be OH in the terminal end. OHCH(C2H5)COOH.
1. Extract dna
2. Using PCR
3. Restriciton enzyme
4. Put in agragose gel
5. Carry out electrophoresis
6. Forgot. Lol.

Doesn't restriction enzyme come before PCR?

 

[beacon_of_light]

@beacon. Yes it is but it supposed to be OH in the terminal end. OHCH(C2H5)COOH.
1. Extract dna
2. Using PCR
3. Restriciton enzyme
4. Put in agragose gel
5. Carry out electrophoresis
6. Forgot. Lol.

Doesn't restriction enzyme come before PCR?

No PCR comes b4 restriction...PCR increases DNA amount and then cut into fragments by restriction enzymes!

 

[Xenon]

ya an addition polymer... CH(OH)--CH3 if I am not wrong
And then the correct structure was CH2(OH)CH3 ...becuz this structure shows positive result with I2(aq) and NaOH(aq) as stated in the qstn

CH3CHO also shows positive iodoform test... i was confused whether the molecular formula will be same for part (c)

 

[skyfox]

@beacon. Yes it is but it supposed to be OH in the terminal end. OHCH(C2H5)COOH.
1. Extract dna
2. Using PCR
3. Restriciton enzyme
4. Put in agragose gel
5. Carry out electrophoresis
6. Forgot. Lol.

Doesn't restriction enzyme come before PCR?

many people have some ans like yours. but i already check it in my A2 level books. and PCR comes first.

 

[skyfox]

B polymer that we have to made it was an addition polymer \..rytttttt????nd after hydrolysis waht was the other strutctre we have to made from formula C2H4O???nd wat was da strucure after ths part in which it was said that Structure C dont declourises bromine but react with iodine i thnk???wat was that i have drwan an aldehyde because with c2h4o only aldehyde was possible.....

Sum1 ans ths plx

ya an addition polymer... CH(OH)--CH3 if I am not wrong
And then the correct structure was CH2(OH)CH3 ...becuz this structure shows positive result with I2(aq) and NaOH(aq) as stated in the qstn

it supposed to be aldehydes. it is stated in CS TOH books.

 

[Xenon]

@beacon. Yes it is but it supposed to be OH in the terminal end. OHCH(C2H5)COOH.
1. Extract dna
2. Using PCR
3. Restriciton enzyme
4. Put in agragose gel
5. Carry out electrophoresis
6. Forgot. Lol.

Doesn't restriction enzyme come before PCR?

No PCR comes b4 restriction...PCR increases DNA amount and then cut into fragments by restriction enzymes!

It does? but the app booklet says "In this technique, after the DNA has been broken up into pieces in the usual way, an individual
segment is extracted. Heating a solution of the segment separates............. " I thought the usual way is to use the enzyme

 

[beacon_of_light]

ya an addition polymer... CH(OH)--CH3 if I am not wrong
And then the correct structure was CH2(OH)CH3 ...becuz this structure shows positive result with I2(aq) and NaOH(aq) as stated in the qstn

CH3CHO also shows positive iodoform test... i was confused whether the molecular formula will be same for part (c)

yeah right but were they talking about oxidation??? or any oxidising agent used! I don remember!

 

[Xenon]

ya an addition polymer... CH(OH)--CH3 if I am not wrong
And then the correct structure was CH2(OH)CH3 ...becuz this structure shows positive result with I2(aq) and NaOH(aq) as stated in the qstn

CH3CHO also shows positive iodoform test... i was confused whether the molecular formula will be same for part (c)

yeah right but were they talking about oxidation??? or any oxidising agent used! I don remember!

oxidation...? i remember just hydrolysis.. though i have no idea how hydrolysis can create an aldehyde. Nevertheless I wrote CH3CHO to match the molecular formula C2H4O

 

[beacon_of_light]

yeah that's wat I am saying... it was hydrolysis and that mainly results in an alcohol :S

 

[boy2011]

but v hav to match the moleculas formula c2h4o nd aldehyde only matchex ths so it must b rite...

 

[Dickinson]

I got this too --> HO-CH(C2H5)-CO2H
Optical isomerism in first,...then cis-trans isomerism...
n it was condensation polymerisation....fr isomer question

 

[beacon_of_light]

yeah ur right the first one was an alkene and then the correct formula was an aldehyde!!!

 

[skyfox]

@XENON
yes it does... When we extract DNA. only small amount of DNA we got. ( STR ). that's why we are using PCR first. then we cut by the restriction enzyme. It was on my mind.

 

[WellWIshER]

AND THEN IT GOES 4 ELECTROPHORESIS

 

[beacon_of_light]

@XENON
yes it does... When we extract DNA. only small amount of DNA we got. ( STR ). that's why we are using PCR first. then we cut by the restriction enzyme. It was on my mind.

Well the usual way is to increase DNA amount first via PCR and then fragment it and that's wat I've read on a couple of sites...dono why Booklet says the other way round ...lets see if the examiner will credit both or not !

 

[bionology]

@XENON
yes it does... When we extract DNA. only small amount of DNA we got. ( STR ). that's why we are using PCR first. then we cut by the restriction enzyme. It was on my mind.

Well the usual way is to increase DNA amount first via PCR and then fragment it and that's wat I've read on a couple of sites...dono why Booklet says the other way round ...lets see if the examiner will credit both or not !

isnt it restriction enzyme first and then PCR?