Chemistry: Post your doubts here!

[nehaoscar]

lol well 1 hour 40 questions is the biggest joke ever told in the history of mankind ,how do you answer something like calculations, i read somewhere to devote 1 minute to a question
lol

Yeah they say 1min per question is ideal but i never used that logic because that just created more tension for me!
Instead don't focus on the time for each question and just leave the questions that you can't do for the last
Do all the ones you can first
For the calculation question if you think you know it attempt it, but then if it's taking too long and if you think it's wrong then leave it for the time being and come back to it later (Star these question so you know which ones to go back to)

 

[awesomaholic101]

How to prepare for paper 5?Any good sites?

http://cieoandalevelnotes.blogspot.in/2015/05/chemistry-level-paper-5-p5-solved-past.html

 

[nehaoscar]

Please explain how to do this one
Metanoia

 

[nehaoscar]

How to find order wrt H+ ??
I found the others as 1 but idk how to do it for H+
Metanoia

 

[nehaoscar]

How to find oxidation number on Carbon using the figure??
Metanoia

 

[My Name]

View attachment 58765
How to find oxidation number on Carbon using the figure??
Metanoia

Can you tell me which paper this is?

 

[nehaoscar]

Can you tell me which paper this is?

Specimen paper 2016

 

[Eugene99]

View attachment 58765
How to find oxidation number on Carbon using the figure??
Metanoia

Since oxygen's oxidation number is taken to be -2
suppose carbon's is x and overall oxidation number of ion as the structure shows is -2. So, here is how we set it up:
( -2x4) + (2x) = -2
-8 + 2x=-2
2x=-2+8
x=+3

 

[My Name]

Since oxygen's oxidation number is taken to be -2
suppose carbon's is x and overall oxidation number of ion as the structure shows is -2. So, here is we set it up:
( -2x4) + (2x) = -2
-8 + 2x=-2
2x=-2+8
x=+3

For the overall wont it be the (-2( + (-2( ?That is we take charge of both the oxygen ions?

 

[Eugene99]

For the overall wont it be the (-2( + (-2( ?That is we take charge of both the oxygen ions?

no...each oxygen ion has -1 charge so for both -1x2 which is -2

 

[nehaoscar]

Since oxygen's oxidation number is taken to be -2
suppose carbon's is x and overall oxidation number of ion as the structure shows is -2. So, here is how we set it up:
( -2x4) + (2x) = -2
-8 + 2x=-2
2x=-2+8
x=+3

Thankyou! Could you help me with these ones too?

View attachment 58763
Please explain how to do this one
Metanoia

View attachment 58764
How to find order wrt H+ ??
I found the others as 1 but idk how to do it for H+
Metanoia

 

[The Sarcastic Retard]

View attachment 58763
Please explain how to do this one
Metanoia

(i) CH3CHO + 2CH3OH <===H+===> CH3CH(OCH3)2 + H2O
At eq.
conc. of CH3CHO = (0.2 - x)
Conc of 2CH3OH = (0.1 - 2x) as 2 moles of it is there so 2x moles will be less.
conc of Acetyl A = x
conc of H2O = x as 1 mole of it is there so x.

 

[Eugene99]

Thankyou! Could you help me with these ones too?

Mr. Retard explained the (a) part and I doubt if I can do the (b) part, maybe I needa revise the equilibrum chapter! is it from there?

 

[nehaoscar]

Mr. Retard explained the (a) part and I doubt if I can do the (b) part, maybe I needa revise the equilibrum chapter! is it from there?

It's from reaction kinetics

 

[nehaoscar]

I don't understand why there will be no change in the beaker with Fe3+/Fe2+
Surely adding SO4- to there will also affect the equilibrium due to the common ion effect...
So why no change??
Metanoia

 

[Eugene99]

It's from reaction kinetics

in fact I haven't covered A2 yet! what I have covered I can answer pretty well

 

[nehaoscar]

in fact I haven't covered A2 yet! what I have covered I can answer pretty well

Haha ok no problem

 

[Catherine_1]

http://cieoandalevelnotes.blogspot.in/2015/05/chemistry-level-paper-5-p5-solved-past.html

Thank you so much!

 

[awesomaholic101]

Thank you so much!

no problem

 

[The Sarcastic Retard]

View attachment 58766
I don't understand why there will be no change in the beaker with Fe3+/Fe2+
Surely adding SO4- to there will also affect the equilibrium due to the common ion effect...
So why no change??
Metanoia

Metanoia