Chemistry paper 1 doubts!!

[balloonsandhighlighters]

Ok i go first !

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s03_qp_1.pdf

questions 39 and 38.

For 38 the answer is B. For 39 it's C.
Why?? Thanks a lot and feel free to put your questions here!!

 

[areebaization]

Ok i go first !

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s03_qp_1.pdf

questions 39 and 38.

For 38 the answer is B. For 39 it's C.
Why?? Thanks a lot and feel free to put your questions here!!

38- the ones that decolourize bromine r unsaturated hydrocarbons so thats our first choice while looking for the answers. The state at room temp. may vary in a homologous series and since all of the hydrocarbons burn in O2 we cant look for the answer with these hints (their too vague)

 

[thats_me]

Ok i go first !

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s03_qp_1.pdf

questions 39 and 38.

For 38 the answer is B. For 39 it's C.
Why?? Thanks a lot and feel free to put your questions here!!

Well, for 38 the one that decolourises would be in the same n the one that doesnt would be in the same so 1 and 3 or 2 and 4, so the ans is 1 and 3 i.e (B)
39 : is C as the one with C=C can be polymerised (Addition polymerisation)

 

[areebaization]

Ok i go first !
For 39 it's C.

C is an alkene that can polymerise with more of its SAME monomer. D can polymerise but it'll need other monomers as well

 

[balloonsandhighlighters]

Well, for 38 the one that decolourises would be in the same n the one that doesnt would be in the same so 1 and 3 or 2 and 4, so the ans is 1 and 3 i.e (B)
39 : is C as the one with C=C can be polymerised (Addition polymerisation)

ok thankyou i get it!

 

[balloonsandhighlighters]

C is an alkene that can polymerise with more of its SAME monomer. D can polymerise but it'll need other monomers as well

ok thank you!

 

[eats zombies]

you guys make me feel bad,i didnt even start hahahahaxx

 

[areebaization]

you guys make me feel bad,i didnt even start hahahahaxx

No big deal we got 2 days for the other pprs and we struggled our way through
You will do that too InshAllah

 

[eats zombies]

Ya having all this time to study is crazy :O i wish we had it for p.p3 or smthin !
thankkkyouuuuxxx and good luck a* studenntt <3

 

[T19]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w06_qp_1.pdf question 11
thanx in advance

 

[thats_me]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w06_qp_1.pdf question 11
thanx in advance

Electrolysis of Conc. Nacl
so Chlorine(Cl-) forms at anode and Hydrogen(H+) forms at cathode
the solution that is collected is Sodium hydroxide
so it wil be A chlorine at anode and Sodium hydroxide collected from cathode

 

[zee009]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_s06_qp_1.pdf question 11. Why is it C?
I feel like am on holiday-.- i can't even finish one past paper.

 

[KaranB]

check the discharge series

 

[sharpwings]

Chemistry paper 1 nov 2009 Q13 . here it is http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w09_qp_11.pdfThe answer is supposed to be D. I don't get it !!
Thanks in advance.

 

[thats_me]

Chemistry paper 1 nov 2009 Q13 . here it is http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Chemistry (0620)/0620_w09_qp_11.pdfThe answer is supposed to be D. I don't get it !!
Thanks in advance.

NaOH forms so at the negative electrode it turns blue/purple & at anode forms chlorine so it becomes colourless (bleached)

 

[sharpwings]

NaOH forms so at the negative electrode it turns blue/purple & at anode forms chlorine so it becomes colourless (bleached)

I understood the part about the chlorine and the bleaching, but I think hydrogen should be formed at the cathode since the solution is aqueous and the less reactive one leaves the solution. I don't know.

 

[thats_me]

I understood the part about the chlorine and the bleaching, but I think hydrogen should be formed at the cathode since the solution is aqueous and the less reactive one leaves the solution. I don't know.

Yes hydrogen does form at cathode but the solution left is also collected from the cathode and the option of hydrogen with chlorine is not there.. ( check the diagram in s2000 Q12 solution Z leaves at cathode )

 

[sharpwings]

Yes hydrogen does form at cathode but the solution left is also collected from the cathode and the option of hydrogen with chlorine is not there.. ( check the diagram in s2000 Q12 solution Z leaves at cathode )

Thank youuu
and i'm sorry, it took awhile till i got it.

 

[thats_me]

Thank youuu
and i'm sorry, it took awhile till i got it.

Ur welcum Oh np

 

[To2a Bahaa]

Guys please I need some help in question 36 Nov 2008 paper 1 , why is it that chlorination couldn't remove the fertliliser? And question 13 in NOV 2009 paper 11, can anyone explain it please?