Physics, Chemistry and Biology: Post your doubts here!

[Ameena Eesa]

anyone got revision notes for physics and chemistry paper 3 i never pass those papers

Pass?

Chem: http://igcse.at.ua/index/igcse_chemistry_notes_arranged_by_topic/0-40
Phy: http://www.physicsatweb.com/index_rev.php?id=igcse

 

[Awesome12]

View attachment 41854

Awesome12

 

[rida.12.!!]

For Chemistry paper 6
The investigation question where we carry out our own experiment
Do we have to write it in an essay format or point form
Thanks

its preferred more to write in essay format!!!

 

[eureka!]

How do I know whether a solvent is organic or not?
Phoenix Blood TheCheeseball [USER=96434]Awesome12 gary221[/USER] Dangerzone00

 

[Awesome12]

How do I know whether a solvent is organic or not?
Phoenix Blood TheCheeseball [USER=96434]Awesome12 gary221[/USER] Dangerzone00

Put NaCl in it. Ionic substances will dissolve in only polar solvents (water), it will be insoluble in organic solvent

 

[esshven]

Put NaCl in it. Ionic substances will dissolve in only polar solvents (water), it will be insoluble in organic solvent

Thanks I have also always wondered about that.

 

[Phoenix Blood]

Put NaCl in it. Ionic substances will dissolve in only polar solvents (water), it will be insoluble in organic solvent

Or rather any ionic substance?

 

[Ameena Eesa]

How do I know whether a solvent is organic or not?
Phoenix Blood TheCheeseball [USER=96434]Awesome12 gary221[/USER] Dangerzone00

i guess u had tagged me

 

[Awesome12]

Or rather any ionic substance?

Yup

 

[The Chill Master]

Guyzzz for chemistry notes

https://www.xtremepapers.com/community/threads/all-things-u-need-to-know-about-chemistry-p6.33395/

 

[totalljerkface]

can somebody please post the old paper answers to paper 4 !! PLEASE!

 

[Akshajistari]

Has anybody noticed that the question style has changed a bit, especially for biology from Oct/Nov 2013?
Ameena Eesa ,
slisjunknown

 

[eureka!]

i guess u had tagged me

Yeah, but then I realized you were the Bio-maniac. Don't worry, I'm gonna haunt you with a torrent of q's when it's bio time.

 

[saaara]

can someone tell me why did they say its ''not chloride'' why its not bromide or iodide in http://papers.xtremepapers.com/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s06_qp_6.pdf QUESTION 5 PART E

 

[Bilal ashraf]

Because In test B (iv) they carried out a test to check if there is a halide (chloride or bromide or iodide) with nitric acid and silver nitrate solution an the obervation was no change so that means it didnt contain chloride or bromide or iodide

 

[saaara]

Because In test B (iv) they carried out a test to check if there is a halide (chloride or bromide or iodide) with nitric acid and silver nitrate solution an the obervation was no change so that means it didnt contain chloride or bromide or iodide

I know this but why does the marking scheme say that I have to write only "not a chloride"!!!!! But never mind now I found the answer anyway

 

[totalljerkface]

Done with paper 42! TODAY! WHEW

 

[omarrabie12345]

I know this but why does the marking scheme say that I have to write only "not a chloride"!!!!! But never mind now I found the answer anyway

What is the answer you found why its not bromide or iodide

 

[saaara]

What is the answer you found why its not bromide or iodide

because we did a test and we found that a white precipitate is formed which means its sulphate but we just suspect, since its white precipitate, that its chloride so we make the halide test and we find that no precipitate was seen so thats why its just chloride

 

[xlnc123]

Copper(II) oxide and carbon are both black solids. Copper(II) oxide reacts with dilute sulfuric
acid to form aqueous copper(II) sulfate. Carbon does not react with dilute sulfuric acid.
You are given a mixture of copper(II) oxide and carbon and access to dilute sulfuric acid.
Plan an experiment to investigate the percentage of copper(II) oxide in the mixture.