Chemistry P31

[alyhamad]

Listen everyone! each nd every one of u is wrong! u knw why? the electrode which is supposed to be oxidised is A NOT B! the examiner never asked oxidation in terms of electrons! the experiment which was going on was actually electroplating! in electroplating object which gets electroplated is always at anode (+) electrode and the object which is decresed in size is supposed to be cathode! were u all sleeping or something? nd electroplating always takes place in a cell! soo ppl who wrote oxidation will take place at + electrode are rite!

So how is it electroplating when there is no battery :|
It is a cell but this type made of the same metals
The cathode is always where reduction takes place,in cell cathode is the + electrode
The anode is -ve electrode,loses electrons dissolve in the solution as ions and electrons
Move along the wire to A.The mass of A reamins constant since the Iron atoms reacting with oxygen are compensated by electrons receiving

I think it shud be 2Ag- + 2Cl- ---> 2AgCl

So,how about dividing your equation by 2:|

For the organic isomers wht did you get?I wrote 1 chlorobutane and 2 chlorobutane

 

[IGCSE O/L student]

yea it was easy but I've around 15 mistakes...will this affect my grade that much?

nah, I don't think so!

 

[EpicLol]

Listen everyone! each nd every one of u is wrong! u knw why? the electrode which is supposed to be oxidised is A NOT B! the examiner never asked oxidation in terms of electrons! the experiment which was going on was actually electroplating! in electroplating object which gets electroplated is always at anode (+) electrode and the object which is decresed in size is supposed to be cathode! were u all sleeping or something? nd electroplating always takes place in a cell! soo ppl who wrote oxidation will take place at + electrode are rite!

B was the cathode! So it was B that was the answer according to ur explanation not A...

 

[IGCSE O/L student]

because it is soluble

calcium carbonate is insoluble
calcium oxide is soluble

 

[EpicLol]

calcium carbonate is insoluble
calcium oxide is soluble

Yea I put because its soluable how many marks was the question?

 

[Mohamed123456789]

Yea I put because its soluable how many marks was the question?

2 marks

 

[IGCSE O/L student]

Ins4n3_G4M3R
i understand your argument, and I put A
but the explanation you gave is wrong. according to your explanation, the object to be plated is the anode. it's actually the cathode.

 

[IGCSE O/L student]

Yea I put because its soluable how many marks was the question?

i don't remember!

 

[WhizAly]

Calcium oxide slightly soluble in water to from a slightly alkaline solution of Ca(OH)2
Calcium carbonate is insoluble so it lasts longer,doesn't increase ph 7,
For the organic isomers ,it was 1 chlorobutane and 2 chlorobutane
CH3-CH2-CH2-CH2CL
CH3-CH2-CH(CL)-CH3

 

[IGCSE O/L student]

Calcium oxide slightly soluble in water to from a slightly alkaline solution of Ca(OH)2
Calcium carbonate is insoluble so it lasts longer,doesn't increase ph 7,
For the organic isomers ,it was 1 chlorobutane and 2 chlorobutane
CH3-CH2-CH2-CH2CL
CH3-CH2-CH(CL)-CH3

are you sure about the calcium hydroxide and calcium carbonate?

 

[WhizAly]

are you sure about the calcium hydroxide and calcium carbonate?

I also added not absorbed by fish!

 

[IGCSE O/L student]

I also added not absorbed by fish!

why don't I ever use mu stupid brains????
arrrgghhhhhhh!!!

 

[IGCSE O/L student]

LoL u have BRAINS !!!

i do???

 

[Osmix1995]

that's what i'm scared about.

nope i think it is gonna be low , many students said it was hard after the exam , and some said it was amazing and they are expecting 50 out of 80 ?? like how is dat amazing ??? xD

and also not everyone "CLAIMING" he did good it means it is true

besides , all the years where low even o/n 2011 which was easier was low so yes it will remain low

 

[IGCSE O/L student]

nope i think it is gonna be low , many students said it was hard after the exam , and some said it was amazing and they are expecting 50 out of 80 ?? like how is dat amazing ??? xD

and also not everyone "CLAIMING" he did good it means it is true

besides , all the years where low even o/n 2011 which was easier was low so yes it will remain low

insha allah!
i really hope you are right!

 

[IGCSE O/L student]

U said BRAINS not one BRAIN

fine:
why don't I ever use mu stupid BRAIN????
arrrgghhhhhhh!!!

 

[AGOGO]

fine:
why don't I ever use mu stupid BRAIN????
arrrgghhhhhhh!!!

yeah thats what i mean

 

[Osmix1995]

no your BRAIN is not stupid
is was just HIBERNATING !!

 

[IGCSE O/L student]

no your BRAIN is not stupid
is was just HIBERNATING !!

are you sure?
whatever the hell it was doing, it chose to do it at the wrong time!!!!

 

[L-Girl]

The reagent that converts alcohol to carboxylic acid.. I wrote potassium dichromate but i forgot to say ACIDIFIED potassium dichromate.. I will get it wrong right?

that's correct, you don't have to write acidified and i'm totally sure about it. you got that right don't worry.