Chemistry: Post your doubts here!

[zahra azam]

Which paper ?

Book qs :/

 

[Mr.Physics]

Book qs :/

Pg ?

 

[zahra azam]

Pg ?

Its not out textbook
Its a qs i found on a diff book on internet

 

[donewithtime80]

8a) (iii) By cross linking polymer chains it means, the link between the polymer chains which would be the same chains up and down............ so the cross link between them: HOCH2(CH2OH)C(CH2OH) CH2OH (thus the power 4 in the ms). The H at the top and bottom come because we r talking about it individually, when combined, the COO gets attached instead.
8c(i) They cause no reduction because they already have OH groups, because the cross linking itself has two OH's, plus, the question says that not every one available side chain is......

Hope it helps

thanx

 

[sj0007]

thanx

Welcome

 

[nehaoscar]

Small doubt which may seem silly
S14-41-Q2-b-ii
So they ask for the units of k

Now is amt^-2 same as mol^-3dm^3 ??

 

[a_wiserME!!]

why is order 1 with respect to [H+]?? TIA

 

[Konstantino Nikolas]

View attachment 59249

why is order 1 with respect to [H+]?? TIA

Consider Experiment 3 and 4

0.2/0.25 = 0.8
3.2/2 = 1.6

We know order is 1 with respect to [CH3CHO] , but rate is double when [CH3OH] is kept constant. This means that rate is increasing twice due to order being 1 with respect to [H+] also.

 

[Konstantino Nikolas]

Small doubt which may seem silly
S14-41-Q2-b-ii
So they ask for the units of k
View attachment 59248
Now is amt^-2 same as mol^-3dm^3 ??

never come across rate eqn using pressure :O
The units of rate = atm s^-1 always in case of pressures, is it?
And i don't think we can equate the mol dm^-3 here since 24 dm^3 of gas is only 1 mol ... not sure though

 

[nehaoscar]

never come across rate eqn using pressure :O
The units of rate = atm s^-1 always in case of pressures, is it?
And i don't think we can equate the mol dm^-3 here since 24 dm^3 of gas is only 1 mol ... not sure though

Oh right i forgot it was pressure!
I was thinking of concentrations for some reason ... :/
Thanks!

 

[Konstantino Nikolas]

Oh right i forgot it was pressure!
I was thinking of concentrations for some reason ... :/
Thanks!

yeah coz we usually use concentrations that's why
no problem xD

 

[a_wiserME!!]

Consider Experiment 3 and 4

0.2/0.25 = 0.8
3.2/2 = 1.6

We know order is 1 with respect to [CH3CHO] , but rate is double when [CH3OH] is kept constant. This means that rate is increasing twice due to order being 1 with respect to [H+] also.

Is it like as if to say that with respect to [CH3CHO] it's 1 and so only if its is 1 with respect to [H+], both together can double the rate?? like 1+1 =2??

 

[FranticAmaze]

Is it like as if to say that with respect to [CH3CHO] it's 1 and so only if its is 1 with respect to [H+], both together can double the rate?? like 1+1 =2??

https://www.xtremepapers.com/commun...st-your-doubts-here.9859/page-753#post-950818

awesomaholic101 ruby_fern donewithtime80 this was the other explanation we were talkin about in class today

 

[Konstantino Nikolas]

Is it like as if to say that with respect to [CH3CHO] it's 1 and so only if its is 1 with respect to [H+], both together can double the rate?? like 1+1 =2??

you got it

 

[Konstantino Nikolas]

https://www.xtremepapers.com/commun...st-your-doubts-here.9859/page-753#post-950818

awesomaholic101 ruby_fern donewithtime80 this was the other explanation we were talkin about in class today

This one's a much more clearly structured mathematical way of doing it ... nice.

 

[The Sarcastic Retard]

http://papers.gceguide.com/A Levels/Chemistry (9701)/9701_s15_qp_43.pdf
4(c)(d) Anyone?

 

[Catherine_1]

View attachment 59127
Hope the pic's not too blurred to read.

No no...It's perfect thanks a tonne!

 

[Konstantino Nikolas]

No no...It's perfect thanks a tonne!

np

 

[Lola_sweet]

Can someone please tell me where 244 came from?

 

[Catherine_1]

Can someone please tell me where 244 came from?

So, I doubt that the marking scheme cites 244 kJ/mol since I think it would be 242 kJ/mol as per the data booklet and that is the enthalpy change of atomisation of Cl2 molecule which you have to take into consideration during the calculation.