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Edexcel A Level Chemistry 2019 Paper 1 Unofficial Mark Scheme

prayformepls

Making This in Advance of the Exam. Any Answers you remember, or want to compare submit it below.

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Reply 1

jp.lk12

What did everyone write for the carbon dioxide buffer question?

Reply 2

jp.lk12

How did everyone feel about that paper? Thought it was okay, not great but could have been a lot worse too.

What did everyone write for the carbon dioxide buffer question?

Reply 3

dontrevise

Paper wasnt too bad but wasnt amazing either, for the co2 increase in the body i didnt get the whole jist but noted all of this down, h2co3 = co2 + h2o
Increase in h2co3 then applied to the buffer equation above, increase therefore further dissociation, of the h2co3 to hco3- and h+. hco3- is removed via the kidneys and thats about as far as i developed it

Reply 4

dontrevise

I know for sure u wont get many responses since this is the less popular exam board for chemistry so if anyone wants to talk about the exam feel free to pm

Reply 5

Evil Homer

TSR Community Staff

Original post by dontrevise

I know for sure u wont get many responses since this is the less popular exam board for chemistry so if anyone wants to talk about the exam feel free to pm

No people are interested it just takes a little while to build up, stay patient, people will come :smile:

How did you find it today?

Reply 6

Fluffer_656

I thought it was a weird paper. Some really easy bits but again some tricky parts. For the H2C03 dissociation I talked about the c02 reacting with HCo2 minus to form further H2C03? Which shifted equilibrium to the left. This caused H2C03 to dissociate further to release C02 and H2O more readily to remove co2 that is toxic in the blood? I'm not sure. I think that might be wrong lol.

Reply 7

ToniADEsewa18

What did people get for kp ..? Because i got a large number

Reply 8

jp.lk12

Original post by Fluffer_656

I think I put it the opposite way around, I think I’m wrong so you’re probably right. And I agree a lot of the questions were quite weird.

Reply 9

prayformepls

Personally it was very bipolar. They were understandable questions, which I knew the answers to, but i think exam technique was a floor. Things with the Potassium Bromide, The Hot NaOH, like i knew it previously in revision, but didnt do so well today. Damn it. Well done guys, lets focus on the next exams! Message me in PM if you want to compare answers privately, or just post here.

Reply 10

TomasD

Like 647000 or something I cant remember how the numbers went but like 650000 somewhere there then atm-1

Original post by ToniADEsewa18

What did people get for kp ..? Because i got a large number

Reply 11

TomasD

2nd question on the paper ... about ppt not all redissolving, whats the answer anyone?

Reply 12

ToniADEsewa18

I got a similar answer phewww . Thank you

Original post by TomasD

Like 647000 or something I cant remember how the numbers went but like 650000 somewhere there then atm-1

Reply 13

TomasD

And for mass of sodium ethanoate, 0.432 g (or something alone these lines)?

Reply 14

maryamakbar

cl ppt dissolves in dilute ammonia but br doesn’t,, br ppt dissolves in conc ammonia i think! :smile:

Original post by TomasD

2nd question on the paper ... about ppt not all redissolving, whats the answer anyone?

(edited 4 years ago)

Reply 15

jp.lk12

The KBr was in excess, so there would still have been Br- ions remaining even after all the Chlorine has displaced bromide ions. Silver bromide doesn’t redissolve in dilute ammonia but silver chloride does. Silver bromide was the remaining precipitate

Original post by TomasD

2nd question on the paper ... about ppt not all redissolving, whats the answer anyone?