identification of an organic unknown coursework

ive done this coursework mostly, but im just a bit confused on how to do the flowchart, if anyone who has done this coursework could help me i would be very grateful

Reply 1

Beenybabe

aaah the organic unknown - mines due in on friday

right...you basically need to come up with a series of tests that eliminates each of the possible unknowns - start with the easy ones like acidity and saturation and then gradually you'll create a flow-chart with them all on. Its easiest to just label each test and then describe them separately to the flow chart.

NB if you are word processing it have your final flow chart pattern done first before you go anywhere near a computer, and if you are a patient kind of person i would suggest just doing it yourself, many people at my school have had serious arguments with word and powerpoint in their attempts to master the flow chart and have resorted to good old pen and paper.

Reply 2

Anarchy Everywhere

Right I require some help on this too, mine's due in on friday. Currently I have...

Bromine water test which shows the alkene. Then the add metal to unknown test which seperates acid, phenol and alcohol from carbonyls and ester. Then I have the sodium bicarbonate test to seperate carboxylic acid from phenol and alcohol. And also the silver mirror test to seperate aldehyde from ketone.

Now I am stuck on how to seperate phenol from alcohol and also need a test for an ester. I'd like to do these without the use of Iron chloride. Also please correct any of the above if I've gone wrong.

Cheers and help before tomorow 8:30 am would be appreciated.

Reply 3

BeesKnees

Tazmanmaniac, you could also test for phenol with the bromine water test to give you a white precipitate.

Reply 4

Anarchy Everywhere

Jesus sweet christ I'm a doorknob, cheers.

Reply 5

Anarchy Everywhere

Ok I've done everything apart from an ester test, from some class notes I have some rough scribblings which says something along the lines of...

'Negative NaHCO3 test - reflux with dilute H2SO4, cool, reflux or react (can't read handwriting) with NaHCO3, acid formed (or another word begginign with f) due to hydrolysis of ester.'

Now can anyone make sense of that or have any knowledge of any tests for esters? I have conflicting reports one saying adding H2NOH and iron chloride will form a blue red complex while another says I need H2NOH with mathanolic KOH and FeCL3 and HCL to give red colour.

Ahhhh.

Reply 6

poppy_bluebell

i didnt realise there was already a thread for this topic.
mines in for this friday too.
can anyone tell me:
1: what concentration of sodium carbonate to use to distinguish between a carboxylic acid and a phenol?
What are the error in observations?
2: What concentration of acidified potassium dichromate should i use to distinguish between a primary and tertiary alcohol?
3: What concentration of 2,4 dnph should be used?
4: What volume of benedicts solution should be used to distinguish between an aldehyde and a ketone. approximately?

What should you do if sodium metal does not react?
how will it be disposed of?
What hazards to Sodium metal have?
What hazards do limewater have?
Are there any hazards for the unknown?e.g. If it is a phenol?

please any help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! :smile:

Reply 7

poppy_bluebell

please help!
thanks in advance!

Reply 8

Zigi

Check out this site:
http://www.wpbschoolhouse.btinternet.co.uk/page13/ChemicalTests/ChemicalTests.htm
It's really useful for this coursework.
Btw, we wern't meant to write volumes or concentrations, jus right in the lines of "concentrated HCL."

Reply 9

poppy_bluebell

i have checked that site and there is not really anything that i am able to use as i used different tests to identify the various compounds.
i know some people have not been asked to find the concentrations of the reagents but my teacher has so if anyone knows them can you plese post the concentration for:
1 :s-smilie:

odium Carbonate
2:Potassium Dichromate
3:2,4 DNPH

also i need an approximate value for the Benedicts.
hazards of the unknown e.g if its a phenol.

Also does anyone know roughly what you need to include in your coursework in roder to gain top marks as my teacher has not given us a guideline of the thhings you need to include in order to gain higher marks. i do know that you need equations in order to get level 8.
im just missing 1 equation now the one for blue litmus.

any help would be appreciated
i have to give this in for friday!