Chemistry paper 4

[shafayat]

I hate the fact we have to do AS organic as well

AS is sooo easy
try A2 OMG every mark scheme has different answers, reactions and conditions :'(

 

[sam1234]

You seem confident about yours answers share them if you remember

Not in a mood to identify more mistakes will share the results on 12 august. Best of luck guys.

 

[shafayat]

can someone explain these observations ?

 

[nimzy95]

I find A2 organic comparatively easier

 

[shafayat]

I find A2 organic comparatively easier

TUTOR MEEE

 

[omarjaved619]

I find A2 organic comparatively easier

Agreed!

My chem paper 2 didnt go extremely well. Kinda disappointed. The paper just felt...different. InshaAllah aiming to make up for it in Paper 4!

 

[Aizah K]

From were the questions were i mean chp ?

 

[sweetjinnah]

itallion stallion

 

[perky1]

52!

chem 52 ??? you are done with it ?

 

[Oishee Asif]

chem 52 ??? you are done with it ?

No, they were talking about Bio P52

 

[Manobilly]

I heard the format is completely differentt

 

[Malik777]

https://www.xtremepapers.com/community/threads/paper-discusion-bio-52.33499/

 

[hela]

what about the most topic we have to study A LEVEL

ANY ONE HAS AN IDEA

 

[hope4thebest]

http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_s11_qp_42.pdf Question 3 (c) part?

 

[Fallen316]

Agreed!

My chem paper 2 didnt go extremely well. Kinda disappointed. The paper just felt...different. InshaAllah aiming to make up for it in Paper 4!

we're on the same page, bro.

 

[sam1234]

I would really appreciate if someone would help me with the configuration of chromium 3+ and manganese 2+ why are the electrons removed from the 4s orbital rather than 3d. Please help.

 

[Aizah K]

anyone done wid p4

 

[Fallen316]

can someone explain these observations ?

as you can see the second compound contains double bonds in the benzene ring while the first compound doesn't. Now you should know this that when Br2 is added to any alkene(double bond) it is decolourised. You should know this if you've done As level organic

when NaNO2/HNO2 + HCl under 5degrees is added to the second compund it forms Benzene diazonium chloride(BDC) . this process is called diazotisation. This is followed by the addition of Phenol under alkaline medium to give Azodye which is the yellow precipitate in the observation

I know this all sounds insane at first but organic is basically Ratta. Just start from 2002 onwards and solve only the organic questions of every paper, you'll get the hang of it i'm sure

 

[Fallen316]

I would really appreciate if someone would help me with the configuration of chromium 3+ and manganese 2+ why are the electrons removed from the 4s orbital rather than 3d. Please help.

alright, see, the maximum electrons d shells and an s shells can hold are 10 and 2 respectively. If d shell contains 5 electrons which is half of the total number of electrons(10) it can hold then it is said to be stable.
So for chromium the electronic configuration is 3d5 4s1, since 3d contains 5 electrons so is more stable than 4s which is also stable but becuase 4s electrons even further from the nucleus, therefore, the 4s electrons are pushed to a higher energy level than 3d.
Same is the case for Manganese.