Edexcel A Level Chemistry 2019 Paper 2 June 11th 2019 Unofficial Mark Scheme

Oh maybe I read the question wrong but I went along the lines that the impurities were blocking the active sites so therefore the reactant molecules couldn’t get in. Noooooo

Original post by Hussain237363

In here I spoke about the adsorption and desorption theory

Reply 61

Yẽncgf

6

Original post by monisha e

I said something like active sites get blocked, won't be able to desorb and impurities attached to active sites too strongly.

I think it is about surface area for adsorption

Reply 62

Dyzzle

9

Original post by monisha e

I said something like active sites get blocked, won't be able to desorb and impurities attached to active sites too strongly.

Yeah idk, the internet is saying that platinum and palladium catalyse in the same way (implying they form nitrogen and oxygen) but then idk where the impurities came from

Reply 63

RickHendricks

19

questions i remembered:

Hexon-2-ol for the iodine
Phosphur has 3 quantum shells, expand octet to 18 electrons, that nitrogen cant do so no PCl5
Ethanal, Ethanoic acid, flavon3ols ketone, and ester betweene ethanoic acid and the flavon-3-ol

Palladium poisonded as the impurities adsorb to the surface and have strong adsorption thus do not deadsorption
less active sides for the reactans so less effective

Crystalisation
the NCl3 and NF3

Reply 64

Beamomom

12

Yeah I said something along those lines too. What did people put for PCl5 forming but not NCL5?

Original post by monisha e

I said something like active sites get blocked, won't be able to desorb and impurities attached to active sites too strongly.

Reply 65

Dyzzle

9

Original post by Yẽncgf

I did this wrong but i think is flavyl ethanoate cause flavanol has no carboxylic group

It is. I think I got about 3 marks in that six marker lol

Reply 66

monisha e

7

Original post by Yẽncgf

I think it is about surface area for adsorption

Oh yeh I said less surface area for reaction to take place as well

Reply 67

RickHendricks

19

Original post by monisha e

Oh yeh I said less surface area for reaction to take place as well

less active sides :smile:

Reply 68

Yẽncgf

6

Original post by RickHendricks

questions i remembered:

Hexon-2-ol for the iodine
Phosphur has 3 quantum shells, expand octet to 18 electrons, that nitrogen cant do so no PCl5
Ethanal, Ethanoic acid, flavon3ols ketone, and ester betweene ethanoic acid and the flavon-3-ol

Palladium poisonded as the impurities adsorb to the surface and have strong adsorption thus do not deadsorption
less active sides for the reactans so less effective

Crystalisation
the NCl3 and NF3

Anythings about optical isomers ? Cause I remember they asked 4 structure of alcohol present and there are 2 chiral carbon

Reply 69

Yẽncgf

6

Original post by RickHendricks

less active sides :smile:

Same thing ???

Reply 70

monisha e

7

Original post by Beamomom

Yeah I said something along those lines too. What did people put for PCl5 forming but not NCL5?

I said something like Cl and N have the same electroegativity. I know it was wrong but I didn't want to leave it blank

Reply 71

Mind73636

3

Original post by Beamomom

14.7/0.31 = 47.419–> which is the required mass of propane if you have a 31% yield and make 14.7g of the other thing. From there just calculate moles of propane then multiply by 24. Can someone explain what is wrong with this ?

That’s percentage by mass which is not the same as percentage of molecules as they have different masses

Reply 72

monisha e

7

Original post by RickHendricks

less active sides :smile:

Yeh I said both less surface area and active sites

Reply 73

Yẽncgf

6

Original post by Sum Mmed

yield 60.3%
mass of carbon 1.7g
k=3.0something mol^2dm^-6s-1
also the last mechanism? i didnt see it in our textbook?
what did you guys circle for 4.8ppm?

The unit for k must be opposite which is dm6 mol-2 to cancel the units of 2 of the molecule involved in RDS

Reply 74

Oko24

5

What’s the maximum marks do u think I get get for the six marker if I didn’t mention names? Drew the ester and ketone structures and mentioned aldehydes and carboxylique acids but didn’t directly name them?

Original post by Dyzzle

It is. I think I got about 3 marks in that six marker lol

Reply 75

Dyzzle

9

Original post by Oko24

What’s the maximum marks do u think I get get for the six marker if I didn’t mention names? Drew the ester and ketone structures and mentioned aldehydes and carboxylique acids but didn’t directly name them?

I reckon you’ll probably be capped at 4 then, maybe five if you’re lucky. It depends on whether they say that naming ethanal and ethanoic acid is one point in total or one point for each. This is assuming you’ve used proper English and structured it correctly obviously

Reply 76

Yẽncgf

6

Original post by Dyzzle

I reckon you’ll probably be capped at 4 then, maybe five if you’re lucky. It depends on whether they say that naming ethanal and ethanoic acid is one point in total or one point for each. This is assuming you’ve used proper English and structured it correctly obviously