Chemistry Paper 4-theory- doubts =D

[PhyZac]

wow thanks a lot for the prayer and same goes to u..inshAllah

anyway for the xray-crystallography is that it only detects areas in the structure with high electron density and hydrogen has only one electron in its structure so it has a very low electron density that the xray can't detect it

Jazaka Allah khairan Againg
And May Allah s.w.t help you and guide you through all obstacles of life, including tomorrows papers! Aameen!

 

[iKhaled]

and iKhaled thought it was a test

haha yeah *facepalm*

 

[iKhaled]

Jazaka Allah khairan Againg
And May Allah s.w.t help you and guide you through all obstacles of life, including tomorrows papers! Aameen!

thanks a lot man and i hope your papers goes well tomorrow too !

 

[PhyZac]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_s12_qp_41.pdf
3 d Why Br on the benzene ring is in position written in the ms? can't put 'em (non-adjacent thou) anywhere? like 1st nd 5th position?
PhyZac
xhizors

I dint get your question, but when you draw Br always try making them non adjacent
they dint matter where to add them though, because it is beyond Alevel syllabus!

 

[knowitall10]

Quick question guys..which comp'ds have the -CH3CO gp?

 

[iKhaled]

i hope tomorrow we don't get anything about chromatography and NANOTECHNOLOGY..any nanotech question will be left completely blank by me :S

 

[iKhaled]

Quick question guys..which comp'ds have the -CH3CO gp?

methyl ketone compounds..can be any compound

 

[AlishaK]

I dint get your question, but when you draw Br always try making them non adjacent
they dint matter where to add them though, because it is beyond Alevel syllabus!

I meant if u see the MS , see the position of br on the benzene ring but we can place br2 on the they possible position too eh? as long as they r adjacent?

 

[PhyZac]

I meant if u see the MS , see the position of br on the benzene ring but we can place br2 on the they possible position too eh? as long as they r adjacent?

Yup yup...!

 

[iKhaled]

who hates "what do u understand by the term or define blabla" questions? YUUCKK

 

[PhyZac]

who hates "what do u understand by the term or define blabla" questions? YUUCKK

I used to hate..now it is mark saving!

 

[knowitall10]

Allah Yawaffagkum!!!
Good Luck for your Chemistry P4 tomorrow!!!
May Allah Succeed us all!!!!!!!!!!!!!!!!!!!!

 

[PhyZac]

knowitall10

Aameeen...
And for Pure 3 too !!

 

[Ramsha007]

plz anyone help me with the ratios of Nmr how do we calculate them like in low resoulution Nmr, ratios of areas under the peak or in mass spectroscopy ratios of peaks of Cl isotopes

 

[iKhaled]

did the forums lagged for u guys now or was it only me ???

 

[PhyZac]

did the forums lagged for u guys now or was it only me ???

Everyone disappeared! look how many online

 

[Silent Hunter]

Any short summary or note for how the pH effect the enzyme activity ?

xhizors
PhyZac
iKhaled
knowitall10

or anyone ?

JazakAllah

 

[PhyZac]

Any short summary or note for how the pH effect the enzyme activity ?

xhizors
PhyZac
iKhaled
knowitall10

or anyone ?

JazakAllah

pH depend on H+ and OH-

As we should know, enzyme is a protein and protein has many bonding in it including ionic interaction.
These ionic interaction will be affected with due to change of pH.

Every enzyme has an optimum pH, (usually at 7), and thus, extreme pH say 1 or 2 for an enzyme with optimum say 7, will denature (make enzyme change shape, including active site shape)

 

[cheondoongiee]

Enzymes are proteins, right? So in their tertiary structure they have ionic bonds. When the pH is increased or decreased, it affects the ionic bonds in the tertiary structure. This can result in the active site changing and reducing enzyme activity or even denature it.

 

[leosco1995]

Please help. I know the value of J is 21 but I couldn't figure out K.