Edexcel A Level Chemistry 2019 Paper 1 Unofficial Mark Scheme

Reply 420

lea.sednem

8

did you guys . have any questions on like autocatalysis, melting and boiling points across and down, pv=nrt ??

Reply 421

Shimo

16

Original post by lea.sednem

did you guys . have any questions on like autocatalysis, melting and boiling points across and down, pv=nrt ??

Yeah there was a 6 marker on why water boils at a higher point than hydrogen sulphide, and a multiple choice on the Mn(II) autocatalysis

Reply 422

lea.sednem

8

thanks do you remember what other topics were in the paper ??

Original post by Shimo

Yeah there was a 6 marker on why water boils at a higher point than hydrogen sulphide, and a multiple choice on the Mn(II) autocatalysis

Reply 423

Shimo

16

Original post by lea.sednem

thanks do you remember what other topics were in the paper ??

There were no questions on transition metal colours, but there was a 6 marker on the difference between how colours occur during a flame test and how they occur with transition metals. I think there was something on Fe(II) catalysts but I can't remember

Reply 424

DevouringDusk

1

Should be 0.45g, many people forgot adding Na (23) in the MMr when trying to find grams

Reply 425

DevouringDusk

1

Was D; [y]^4/[x]^4

Original post by Munrhe

Amazing. Thank you. Did you remember last MS? C or D?

Reply 426

TomasD

12

Is there a forum for paper 2?

Reply 427

dontrevise

9

Original post by TomasD

Is there a forum for paper 2?

Yeah go into the chemistry sub section and youll find a level edexcel paper 2

Reply 428

kekedoyouloveme?

21

it wasnt as bad as paper 1 ig...

what did everyone put for why the catalyst is ineffective w impurities, i said oh because impurities bind to the surface of catalyst, by adsorption but the bonds dont break, and so impurities dont leave the catalyst by desorption, also impurities block the reactant molecules from binding on to the catalyst surface by adsorption, and so more energy required to remove the impurities, from the catalyst so it slows down the rate of a catalysed reaction

do you think this would be like a 1/3 or a 2/3 you reckon?

Reply 429

azozarmen

9

You are right about impurities absorbing and then not desorbing, but the reason why the catalyst is not as effective is because the effective surface area is decreased (less active sites). I'd say you would get 2 marks because you said the impurities adsorb and form strong bonds so do not undergo desorption.

Original post by kekedoyouloveme?

it wasnt as bad as paper 1 ig...

what did everyone put for why the catalyst is ineffective w impurities, i said oh because impurities bind to the surface of catalyst, by adsorption but the bonds dont break, and so impurities dont leave the catalyst by desorption, also impurities block the reactant molecules from binding on to the catalyst surface by adsorption, and so more energy required to remove the impurities, from the catalyst so it slows down the rate of a catalysed reaction

do you think this would be like a 1/3 or a 2/3 you reckon?

Reply 430

Kategrinding

1

The proportion is constant as the concentration is high? And a few equations.

Reply 431

VAking

1

I agree with that except that the concentration of H+ increases too, but since Kw=[H+][OH-], the concentration of OH- increases to the same number as temperature rises and neutral solutions mean that [H+]=[OH-] and hence it is neutral

Original post by byrnm051.308

I think it’s neutral because although the pH changes, the concentration of OH and H+ do not change so it is neutral