Chemistry: Post your doubts here!

[Suchal Riaz]

Suchal Riaz

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w11_qp_12.pdf

9(D),36(D),39(C)

in 36 spontenously means 'by itself' it means that unlike SO2→SO3 which needs a catalyst it happens naturally. so it must be NO→NO2
Nitrogen has two of it's electron bonded. rest of the three are like 2 paired and one unpaired.

39:
in (2) the ester will hydrolyse to form ethanoic acid and methanol. in (3) the nitrile will hydrolyse with alkali to make CH3CO2 and with H+ it will make ethanoic acid too. in (1) substituition or elimination will take place with aqueous OH

 

[roxylara]

Someone please explain these 3 to me

 

[sweet.sugar]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s12_qp_12.pdf
Q6-c ( i got D 21.6 i did the calculation twice got 0.06 mol 7dm^3 and temp 303 n calcultaed it using them )
Q20-c (plz write the calculation)
Q24-A ( octene ha c8h18 so wen it cracks the products will add up to be with in the molecular formula of octene ryt)
Thanks.

 

[Suchal Riaz]

You dont say! :O

Anyways
Plz
https://www.xtremepapers.com/community/attachments/45117/
Ans is c, how?

all C=C can show cis-trans
it's more like permutation of mathematics.
first C=C can be cis and trans, second can be either, third can be either
there are two arrangements for first, two for second and two for third: 2*2*2=8

 

[Suchal Riaz]

i think they r nt available

please remove your signature it makes it more difficult to scroll as it makes the page bigger. and it's agains the rules: Terms and Rules

 

[MYLORD]

C

can u help me solve this
ans is c

 

[_Ahmad]

Bro dont waste your time on already answered questions

Don't say like this. You should have checked the question if it is repeating or not before asking.
now he spend his time to solve your doubt so you should appreciate him instead of saying like this

 

[_Ahmad]

in 36 spontenously means 'by itself' it means that unlike SO2→SO3 which needs a catalyst it happens naturally. so it must be NO→NO2
Nitrogen has two of it's electron bonded. rest of the three are like 2 paired and one unpaired.

39:
in (2) the ester will hydrolyse to form ethanoic acid and methanol. in (3) the nitrile will hydrolyse with alkali to make CH3CO2 and with H+ it will make ethanoic acid too. in (1) substituition or elimination will take place with aqueous OH

Thanks alot

 

[Zepudee]

the same questions are asked again and again.
27:
the alcohol is tertiary and have a chiral carbon with least number of carbons: so chiral carbon has one CH3 one OH one C2H5 and one C3H7 attached to it. this is the only way to make the n smallest and still have a teriary alcohol with chiral carbon
8:density depends on Mr. the average Mr of D looks high as it has highest percentage of CH3.
24:
CH3CHO→CH3CH(OH)CN->CH3CH(OH)CO2H→CH3CH(OH)CO2CH3(esterification)

Thank you so much suchal riaz! and sorry for bothering you.

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w11_qp_12.pdf
Q26 (A), Q30 (A)

THANK YOU SO SO MUCHHHHHH!! please help

 

[Suchal Riaz]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_12.pdf
Q6-c ( i got D 21.6 i did the calculation twice got 0.06 mol 7dm^3 and temp 303 n calcultaed it using them )
Q20-c (plz write the calculation)
Q24-A ( octene ha c8h18 so wen it cracks the products will add up to be with in the molecular formula of octene ryt)
Thanks.

number of moles = 0.96/32=0.03 moles
P=nRT/V=.03moles*8.31*(273+30)K / 7000x10^-6 m²=10.7KPa

 

[..sacrifice4Revenge..]

Don't say like this. You should have checked the question if it is repeating or not before asking.
now he spend his time to solve your doubt so you should appreciate him instead of saying like this

K ahmad,K, my doubt? K.

 

[GCE As and a level]

please remove your signature it makes it more difficult to scroll as it makes the page bigger. and it's agains the rules: Terms and Rules

How is it against the Term and Rules ??!.............Many people have a signature like this
Also..there is a better way to ask me to remove it

 

[ashcull14]

+1 to this,
Ans is C

sorry, didnt get u...how is it c cn u plx explain

 

[ashcull14]

Its the old rule of electrochem, the one in O levels.
Remember the order, K,Na,Ca,Mg,Al,Zn,Fe,Pb,i dnt remember,Cu,
So Cu is more electro positive than Al and will be reduced at cathode, and vice versa

thnks

 

[Suchal Riaz]

How is it against the Term and Rules ??!.............Many people have a signature like this
Also..there is a better way to ask me to remove it

i was requesting you to remove it and also telling you about rules. i wasn't threatening you. if you won't remove it then go ahead do whatever but don't waste my time i have to solve doubts of other people.

 

[..sacrifice4Revenge..]

ashcull14
Thank sachal for this

all C=C can show cis-trans
it's more like permutation of mathematics.
first C=C can be cis and trans, second can be either, third can be either
there are two arrangements for first, two for second and two for third: 2*2*2=8

 

[GCE As and a level]

i was requesting you to remove it and also telling you about rules. i wasn't threatening you. if you won't remove it then go ahead do whatever but don't waste my time i have to solve doubts of other people.

Is this POLITE way to reply ??!
Just think and answer ur self . Dont reply here cuz this is for CHEMISTRY DOUBTS
ANYWAY, I will remove RESPECTING THE RULES

 

[..sacrifice4Revenge..]

i was requesting you to remove it and also telling you about rules. i wasn't threatening you. if you won't remove it then go ahead do whatever but don't waste my time i have to solve doubts of other people.

Chill out man
You do realise that the rules also state that no user can act as a moderator

You should have just requested him and not brought rules in.
Peace now!
GCE As and a level bro please remove the pic if possible or otherwise make it a bit smaller.thanks

 

[ashcull14]

cn smone explain y isnt it carbon?

 

[ZaqZainab]

all C=C can show cis-trans
it's more like permutation of mathematics.
first C=C can be cis and trans, second can be either, third can be either
there are two arrangements for first, two for second and two for third: 2*2*2=8

how do you know about permutation that much you dont even take stats
but great trick there i didn't realize it myself