AS Chemistry- helping each other out!

Is anyone here participating in the Chemistry Olympiad? :biggrin:

Reply 521

Heretohelp!

9

Yep

Posted from TSR Mobile

Reply 522

Heretohelp!

9

Original post by haemo

AQA?

Yep!

Posted from TSR Mobile

Reply 523

Original post by Heretohelp!

Yep

Posted from TSR Mobile

Aren't the papers similar to the Cambridge Chemistry Challenge Lower Sixth Comp papers?

Reply 524

zara1234567

2

Anyone done Chem ocr AS any of the papers like qual quant or evaluative please PM me because I need like advice. I've done the quantitative but like unsure what to revise for the other two :/

Also if you want earlier past papers which aren't on the ocr website can we get these?

Reply 525

Dylann

Original post by zhang-liao

Aren't the papers similar to the Cambridge Chemistry Challenge Lower Sixth Comp papers?

The format (font, style, layout etc) is basically the same though the questions are more difficult. How are you preparing?

Reply 526

Original post by Dylann

The format (font, style, layout etc) is basically the same though the questions are more difficult. How are you preparing?

I just found out I was going to do it this week, so far I've been looking at past papers, how about you? Haven't done much revision for it though :colondollar:

Reply 527

Dylann

Original post by zhang-liao

I just found out I was going to do it this week, so far I've been looking at past papers, how about you? Haven't done much revision for it though :colondollar:

Past papers, advanced starters for ten, youtube, general revision etc

Reply 528

Dinaa

OP

17

Started Unit 2 and its awesome :awesome:

I have got a question though.

Hexan-1-ol was heated gently with a mixture of potassium dichromate and sulphuric acid. The product of the reaction was distilled off as it formed. Give the structural formula of the product and name it.

So I was thinking, it becomes an Aldehyde, because the question didn't say anything like 'excess' potassium dichromate, etc.. But Idk i'm just wondering.. Aldehyde or Carboxylic acid? :angelblush:

Original post by Dylann

x

Please

(edited 9 years ago)

Reply 529

S F

7

It would be an aldehyde because its being distilled off and a carboxylic acid if it was a reflux

Posted from TSR Mobile

Reply 530

Super199

Anyone care to help me with the following.

Give the structure and name of every haloalkane that could be produced by the reaction of methane with chlorine.

Reply 531

F1's Finest

Original post by Dinaa

Started Unit 2 and its awesome :awesome:

I have got a question though.

Hexan-1-ol was heated gently with a mixture of potassium dichromate and sulphuric acid. The product of the reaction was distilled off as it formed. Give the structural formula of the product and name it.

So I was thinking, it becomes an Aldehyde, because the question didn't say anything like 'excess' potassium dichromate, etc.. But Idk i'm just wondering.. Aldehyde or Carboxylic acid? :angelblush:

Please

The word that gives you a massive hint is 'distilled'.

Oxidation under a distillation setup would yield an aldehyde.

If however the question hinted that the apparatus would be under reflux, you should immediately know that the final oxidised product will be a carboxylic acid. Apparatus for reflux.

Here is a diagram that shows both of em side by side.

Don't be thrown by the question mentioning 'excess' or not. Just remember that you can control what the final product is formed just by changing the apparatus :tongue:

Reply 532

Disney0702

9

Hello everyone!

I did AQA AS Chemistry last year and I got a grade A.

I would like to pass on some advice.

To help me get by I used the CGP textbook revision guide which I found incredibly useful and the way they explain the content is really detailed.

AS Level Chemistry for AQA: Student Book

Sample Pages

I also understand that not all of you do AQA Chemistry but instead from a different exam board so I thought it was best to show you guys the other CGP editions for different exam boards for AS Chemistry in this link.

Good luck with your exams! :smile:

(edited 9 years ago)

Reply 533

SFarooq

5

I have a question that is asking to write an equation for incomplete combustion that produces only gaseous products. What are the gaseous products? Can CO and CO2 both be products of that same equations or is there others.
Thanks

Posted from TSR Mobile

Reply 534

Dylann

Original post by SFarooq

I have a question that is asking to write an equation for incomplete combustion that produces only gaseous products. What are the gaseous products? Can CO and CO2 both be products of that same equations or is there others.
Thanks

Posted from TSR Mobile

It's incomplete so it can only produce H2O and either solid carbon or CO. However since the products must be gaseous it must be CO...

Posted from TSR Mobile

Reply 535

SFarooq

5

So CO AND CO2??

Posted from TSR Mobile

Reply 536

HAnwar

17

Original post by SFarooq

So CO AND CO2??

Posted from TSR Mobile

What is the actual question. For incomplete combustion you can only form carbon monoxide and water.

Reply 537

jshep000

15

Original post by SFarooq

So CO AND CO2??

Posted from TSR Mobile

I'm guessing you had the Edexcel mock like myself? When its complete combustion it forms CO2 (carbon dioxide), when its incomplete combustion is forms CO (carbon monoxide)

Reply 538

Hayley Williams

12

Original post by Dinaa

Started Unit 2 and its awesome :awesome:

I have got a question though.

Hexan-1-ol was heated gently with a mixture of potassium dichromate and sulphuric acid. The product of the reaction was distilled off as it formed. Give the structural formula of the product and name it.

So I was thinking, it becomes an Aldehyde, because the question didn't say anything like 'excess' potassium dichromate, etc.. But Idk i'm just wondering.. Aldehyde or Carboxylic acid? :angelblush:

Please

Hexanal would form. Heat under reflux = carboxylic axid. Distillation = aldehyde.

Posted from TSR Mobile

Reply 539