Chemistry: Post your doubts here!

[manutd96]

http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_s08_qp_1.pdf

question 36, isn't it that nitrogen should have negative oxidation number as it is more electronegative hence it should be oxidised?

Ans given is c (2,3)

 

[bludlynsolja]

Thx a lot much appreciated

 

[Charlotte20102013]

for Qu 14 its B because :
in reaction 1 theres bond breaking so its endo
in reaction 2 theres bond formation so its exo

for Qu 8 its A because:
it neutralises the H+ in both reactions..so its a base.
the quest is about BOTH reactions here. so A is correct

TYVM!

 

[Charlotte20102013]

When I name an organic compound, how do I apply the numbering? Like if thrs a functional group, the numbering follows the functional group.
But what if there was 2 different functional groups in a compound, which do I follow? Like acid or carbonyl group or carboxyl group etc. Which functional group gets the priority?
Thanks.

 

[iYuuki]

Question 39
http://papers.xtremepapers.com/CIE/...d AS Level/Chemistry (9701)/9701_w08_qp_1.pdf

Can someone help?

 

[RoOkaYya G]

TYVM!

welcome

 

[princess Anu]

Somebody please explain how to solve such Questions

 

[Maqb0ol]

Somebody please explain how to solve such Questions

Only 1 is correct. Am i right?

 

[Maqb0ol]

Somebody please explain how to solve such Questions

Only 1 is correct. Am i right?

 

[yasoob_shah]

Thts me!!

 

[Charlotte20102013]

Need a little help here guys...
http://papers.xtremepapers.com/CIE/... AS Level/Chemistry (9701)/9701_w12_qp_13.pdf
Q38 [Ans: B (1&2)] I know option 1 undergoes redox, but how to tell if option 2 undergoes redox?

 

[huh]

Need a little help here guys...
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w12_qp_13.pdf
Q38 [Ans: B (1&2)] I know option 1 undergoes redox, but how to tell if option 2 undergoes redox?

CH4 + Cl2 = CH3Cl + HCl
Cl2 reduced to form Cl(-).
C(4-) in CH4 oxidized to C(2-) in CH3Cl.
Hope this helped.

 

[princess Anu]

Only 1 is correct. Am i right?

Yes!

 

[Maqb0ol]

Yes!

It's easy, just follow the instructions, it says from U to R which means the direction would change (arrow) and positive enthalpy would be reversed by sign. whereas 2nd option is wrong because endothermic is donated by +ve sign

 

[Charlotte20102013]

CH4 + Cl2 = CH3Cl + HCl
Cl2 reduced to form Cl(-).
C(4-) in CH4 oxidized to C(2-) in CH3Cl.
Hope this helped.

Ahhh... Now I get it.. Thank you!

 

[princess Anu]

It's easy, just follow the instructions, it says from U to R which means the direction would change (arrow) and positive enthalpy would be reversed by sign. whereas 2nd option is wrong because endothermic is donated by +ve sign

Can u explain clearly why 2nd is wrong? I did the calculation for it like if we're going from T to S we can use T-U and U-S so (-75+92=+17) the answer is + so can be endo, no?

 

[princess Anu]

the answer is A . somebody plz explain why others are wrong?

 

[savera]

could anyone explain Q3(c)(i)(ii)?

 

[princess Anu]

why are we dividing y by 2??

 

[100]

somebody please if you have the chemistry standards booklet please upload it! NEED IT ASAP!!