Edexcel IGCSE Chemistry 18th May/June 2017 Thread

sad2017

Anu clues about today chemistry paper

What are the conditions for cracking that we need to know? (heat and pressure)

What are the conditions for the production of ethanol?

Reply 42

Msnotorious

14

Original post by holly24601

What are the conditions for cracking that we need to know? (heat and pressure)

What are the conditions for the production of ethanol?

Cracking ; Temperature : 600-700 Celsius , Pressure: 1 atm (normal pressure) , Catalyst: Al2O3 or SiO2

Ethanol: Industrial Method: Temperature: 300 Celsius, Pressure 60 atm, Catalyst: H3PO4
Ethanol: Fermentation Method: Temperature:30-35 Celsius, Catalyst: Yeast, Anaerobic conditions

Reply 43

holly24601

7

Original post by Amandipeiris

Cracking ; Temperature : 600-700 Celsius , Pressure: 1 atm (normal pressure) , Catalyst: Al2O3 or SiO2

Ethanol: Industrial Method: Temperature: 300 Celsius, Pressure 60 atm, Catalyst: H3PO4
Ethanol: Fermentation Method: Temperature:30-35 Celsius, Catalyst: Yeast, Anaerobic conditions

Thank you!

Reply 44

username2973666

12

Original post by Amandipeiris

Cracking ; Temperature : 600-700 Celsius , Pressure: 1 atm (normal pressure) , Catalyst: Al2O3 or SiO2

Ethanol: Industrial Method: Temperature: 300 Celsius, Pressure 60 atm, Catalyst: H3PO4
Ethanol: Fermentation Method: Temperature:30-35 Celsius, Catalyst: Yeast, Anaerobic conditions

Ethanol is paper 2

Reply 45

graceeeee5

14

GOOD LUCK EVERYONE ❤️

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Reply 46

Tatsien

13

Best of luck! 2 hours until the exam

Reply 47

ioriiii773

7

Good luck everyone!!!

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Reply 48

fernsehturm

9

How did everyone find the exam? I thought it went pretty well. Especially compared to Biology!

One question though...why do you put the glass rod in the solution!?

Reply 49

daniel185

My answer was that you should use the glass rod to feel if crystals have been formed - wasn't confident with the answer though

Reply 50

solark

15

What did you get for x?

Reply 51

MarimbaMofo

7

I got 7, i think :smile:

Reply 52

graceeeee5

14

I got 5 but not sure about that - got two different answers!

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Reply 53

solark

15

I found it somewhat difficult compared to the past papers ive been doing..

Reply 54

solark

15

Original post by MarimbaMofo

I got 7, i think :smile:

Me too but it was a decimal that rounded up to 7

Reply 55

MarimbaMofo

7

Original post by solark

I found it somewhat difficult compared to the past papers ive been doing..

Me too, there were quite a few 3 mark experiment questions that I didn't really have a clue how to answer :/

Reply 56

Darwinion

12

I struggled with 3 bits. What did people put for the very last question as to the 2nd reason for increase in rate of reaction as temperature increased?

I started to write that the teacher must have broken up the solid in smaller chunks, but then crossed it out as I figured that would increase the rate regardless of temp.rise. Plus the fact that it had already been touched upon with the iron filings in another question, so thought they wouldn't ask the same thing twice :tongue:

So I ended up putting that the water particles receive more kinetic energy as the temp.increased so they breach the activation energy required more easily.

Also I'm not confident about m,y answer to the ionic equation they asked us to write. I ended up putting: 2Na+ + At2- plus Cl2 gives 2(Na+ Cl-) plus At2. Something like that anyway.
Dunno if I'd be penalised for putting in the sodium spectator ions.

And the magnesium sulfate crystals question... what did peeps put for the formulae of the 2 substances in the filtrate?
I put water (H20) that wasn't crystallised and also MgS04. I nearly put sulfuric acid in case it was in excess but the question didn't state that.

(edited 6 years ago)

Reply 57

k.ee.n.a

2

Original post by Darwinion

I struggled with 3 bits. What did people put for the very last question as to the 2nd reason for increase in rate of reaction as temperature increased?

I started to write that the teacher must have broken up the solid in smaller chunks, but then crossed it out as I figured that would increase the rate regardless of temp.rise. Plus the fact that it had already been touched upon with the iron filings in another question, so thought they wouldn't ask the same thing twice :tongue:

So I ended up putting that the water particles receive more kinetic energy as the temp.increased so they breach the activation energy required more easily.

Also I'm not confident about m,y answer to the inonic equation they asked us to write. I ended up putting: Na+ + 2At- plus Cl2 gives Na+ Cl- plus At2
Dunno if I'd be penalised for putting in the sodium spectator ions.

And the magnesium sulfate crystals question... what did peeps put for the formulae of the 2 substances in the filtrate?
I put water (H20) that wasn't crystallised and also MgS04. I nearly put sulfuric acid in case it was in excess but the question didn't state that.

i know right I found it hard too! Especially the last question - there I talked about more frequent and successful collisions, and also the fact that the ethyne gas expands in hot temperatures...that was a guess! I didn't want to say 'so less space so the particles collide more' because sometimes in qs like that if you put that you get 0/3...So hard!!