Edexcel CHEMISTRY DOUBTS!!!!

[Romeesa-Chan]

1 -
A molecule is polar if it has an overall charge i.e. the charge on the individual bonds do not cancel out.

You are confusing two terms, dipolar = dipoles and polarity is a different thing.
Water has a dipole nature i.e. seperation of charges which results in the water molecule being polar.

No where does the book says that water is not polar but dipolar.

2 - Well, I am just going to explain everything cause your question is very confusing :s

First of all, Oxygen is NOT the highest electronegative atom, it is Flourine.

Electronegativity is a measure of the attraction its atom has for a pair of electrons in a covalent bond.

Oxygen is more electronegative than Hydrogen therefore it will have greater attraction for the electrons in the covalent bond.

Just think about it,
Example, A neutral element like Chlorine (Cl). What will be the charge if it gains an electron? It will be negative.

Oxygen will therefore become slightly negative as the electron are more towards oxygen (it doesnt become negative, it will just have a dipole due to seperation of charges).
Hydrogen therefore becomes positive charge because electrons are away from it.


No one ever mentioned lone pairs, you are again confusing 2 things. Lone pairs determine the shape of the molecule.

Agreed. (:

[SZM]

i dont agree completely with what angl31 said.

may I know whether u have done Edexcel AS and A2 units both for Chemistry and Biology in exam??? Because whatever u r telling, some parts I agree, some parts i dont.
Because my teacher has explained to me in different ideas. Comparing ur ideas and my teacher ideas are not similar, because some parts i cannot agree , that means some parts i still didnt get what u mean//

could u please explain much more clear in details. Pleasssse.... Explain in a beautiful way ,so that i can understand much better. Please dont write short form . Write proper English. Sometimes I dont understand if u write in short form.

Please explain much more clear in step by step. Pls mention while you are explaining, that i should not say or write like this. please mentioned it, so that i will learn, what are the mistakes I have done and what are the concepts or ideas , I have misunderstood.

Please. I need your reply urgently..

Wasalaam

[~ Miss Relina ~]

^SZM

Ang3l is right.....her way is simple and clear I don't find any confusion .......  

I prefer you search any websites to ensure that

[~ Miss Relina ~]

^SZM

Ang3l is right.....her way is simple and clear I don't find any confusion .......  

I prefer you search any websites to ensure your doubt

 and to other guys plz if you are able to do it inform me plz 

[Mike Benn]

Salam alikum Everyone.,

Actually my question is regarding the last chapter NMR and Chromatography Unit 4., i just have to ask for some notes on these topics if anyone is having as the book ( George Facer ) lacks some points.

Will be Grateful if helped

[KJ1995]

Hello guys, I just want check what are the internal assessment tasks, im doing u4 chemistry in january, do they help and should i do them?
Thank you

[KJ1995]

Salam alikum Everyone.,

Actually my question is regarding the last chapter NMR and Chromatography Unit 4., i just have to ask for some notes on these topics if anyone is having as the book ( George Facer ) lacks some points.

Will be Grateful if helped

This should be heplful, credit go to the person i got it from, i think from this forums

[KJ1995]

I also want to ask, how should i know which technique to use when measuring the rate of reaction..it can be confusing because for example: If bromoethane reacts with hydroxide ions, electrical conductivity method can be used thats whats in the book and i agree, however a similar multiple choice question in one of the papers was the hydrolysis of  bromobutane with hydroxide ions.. and i hat to choose the best method, i chose electrical which i think it works but the answer was titration with acid..I want to know when to use whats best in any situation.

THANKS IN ADVANCE :DDDD

[Deadly_king]

I also want to ask, how should i know which technique to use when measuring the rate of reaction..it can be confusing because for example: If bromoethane reacts with hydroxide ions, electrical conductivity method can be used thats whats in the book and i agree, however a similar multiple choice question in one of the papers was the hydrolysis of  bromobutane with hydroxide ions.. and i hat to choose the best method, i chose electrical which i think it works but the answer was titration with acid..I want to know when to use whats best in any situation.

THANKS IN ADVANCE :DDDD

Your answer lies in you own post

The book said that electrical conductivity method CAN be used However it never mentionned that this was the best method

In any case where an acid and a base are involved, titration is best since it is most accurate and less expensive as well as less risky

Hope it helps

[KJ1995]

Your answer lies in you own post

The book said that electrical conductivity method CAN be used However it never mentionned that this was the best method

In any case where an acid and a base are involved, titration is best since it is most accurate and less expensive as well as less risky

Hope it helps

Thank you very much, i just want to maek sure of something.. you said in any case were acid and base are used i should use titration method, but here not both are acids and base, only the hydroxide ion is the base. Or do u mean when there is an acid OR base i should use titration method?

[Deadly_king]

Thank you very much, i just want to maek sure of something.. you said in any case were acid and base are used i should use titration method, but here not both are acids and base, only the hydroxide ion is the base. Or do u mean when there is an acid OR base i should use titration method?

Anytime

Yeah, you got it right

Whenever there is an acid OR a base involved, it is best to use titration method

[~ Miss Relina ~]

This should be heplful, credit go to the person i got it from, i think from this forums

wow ............really it's very helpful  
Thanks alot pal  
 Have you got notes similar to that one for unit 5 I wonder if you can post it soon plz  

[~ Miss Relina ~]

anyone plz this time do reply me
I need anywebsites that help wiyh that point asked by the syllabus
here it is :
.   explain why the development of new catalysts is a priority area for chemical research today and, in this context, explain how the scientific community reports and validates new discoveries and explanations, eg the development of new catalysts for making ethanoic acid from methanol and carbon monoxide with a high atom economy (green chemistry)

Thanks in advance 

[Malak]

i dont agree completely with what angl31 said.

may I know whether u have done Edexcel AS and A2 units both for Chemistry and Biology in exam??? Because whatever u r telling, some parts I agree, some parts i dont.
Because my teacher has explained to me in different ideas. Comparing ur ideas and my teacher ideas are not similar, because some parts i cannot agree , that means some parts i still didnt get what u mean//

could u please explain much more clear in details. Pleasssse.... Explain in a beautiful way ,so that i can understand much better. Please dont write short form . Write proper English. Sometimes I dont understand if u write in short form.

Please explain much more clear in step by step. Pls mention while you are explaining, that i should not say or write like this. please mentioned it, so that i will learn, what are the mistakes I have done and what are the concepts or ideas , I have misunderstood.

Please. I need your reply urgently..

Wasalaam

I have done AS chemistry and I am doing A2.

Can you explain me in a better way, what did you not understand?Just saying that you didn't is too vague for me to reply.

By the way, I haven't used any short forms in my answer and I think my english was quite proper as others understood it.

[KJ1995]

Anytime

Yeah, you got it right

Whenever there is an acid OR a base involved, it is best to use titration method

Thanks