[heyjude_]

I need help with my orgo lab My lab says: You are given a mixture consisting of 10 ml anisole(methoxybenezene), 2.0 g benzoic acid and 0.2 g fluorenone. Devise a method to separate and isolate the anisole and benzoic acid. You may use the following techniques: distillation, extraction,recrystallization. The following chemicals and equipments will be available to you: Chemicals Equipment 2.5 M NaOH filter paper, regular and fluted 3.0 M HCl heating mantles, variacs anhydrous magnesium sulfate
oven at 100 degree C tert-butyl methyl ether (max 25ml) explosion proof hotplates ethanol stirrer hot plates ice thermometers sand vigreux column I know i can dissolve the mixture in ether and wash with NaOH and extract the benzoic acid with the HCl but how do I separate the last two components? I dont have other chemicals to extract the fluorenone. Any help will be extremely appreciated.

[Sophia7X]

You only need to isolate anisole and benzoic acid. Looks like you've got benzoic acid down.

The problem is not extracting fluorenone. The real problem is to just isolate anisole. Extracting fluorenone imples that you need to get isolated fluorenone separated out. The chemical reagents you are given won't be very helpful except MgSO4 (drying agent) in isolating anisole from anisole and fluorenone.

Check their boiling points and melting points.
Could you just evaporate fluorenone out? Could you use recrystallization? Are the two soluble or insoluble in each other? Remember, if both chemicals are soluble in the solvent, regardless if solvent is cold or hot, you can't use recrystallization.

[heyjude_]

I figured this might work based on the lower boiling point of the anisole.
Procedure
Place mixture in 50 mL erlenmeyer flask
Add 20 mL tert-butyl methyl ether to erlenmeyer flask and dissolve mixture
Place solution in separatory funnel
Wash solution with 20 mL NaOH, venting frequently
Extract aqueous layer into 100 mL beaker
Repeat wash with another 20 mL NaOH, venting frequently
Extract aqueous layer into the 100 mL beaker
Add HCl to the 100 mL beaker containing the combined aqueous layers until the solution turns acidic as can be determined with pH paper
Place beaker into 250 mL beaker containing ice water and allow precipitate to form
Vacuum filter using Buchner funnel and filter paper for at least 5 minutes
Rinse beaker with ice water to ensure complete transference
Take filtered crystals and place on oven safe plate
Place plate in oven for 10 min or until crystals are dry
Determine mass of collected crystals and calculate yield
Determine the melting point of collected crystals using the Mel-Temp apparatus
Compare experimental melting point to literature value
Return to separatory funnel and place ether layer into a 50 mL beaker
Add anhydrous magnesium sulfate to beaker
Gravity filter solution using a funnel and fluted filter paper into 100 mL erlenmeyer flask
Place erlenmeyer flask onto explosion proof hot plate and boil off ether
Transfer remaining solution into 50 mL round bottom flask
Assemble distillation apparatus
Attach connecting adaptor with keck clip
Insert thermometer and thermometer adaptor
Connect condenser with water tubes
Add vacuum adaptor open to atmosphere with keck clip
Connect 25 mL receiving flask with keck clip
Apply heating mantle to round bottom flask
Collect distillate in receiving flask recording temperature as it passes through
Remove receiving flask and place in fume hood to cool down
Determine weight of distilled anisole via tared flask and calculate yield
Transfer anisole to 25 mL volumetric flask
Rinse anisole flask with 5 mL ethanol two times and add to volumetric flask
Fill volumetric flask with ethanol, stop it and mix
Fill a polarimeter tube with ethanol solution, ensuring no bubbles are present
Measure optical rotation of the sample, note temperature
Calculate concentration of sample
Calculate specific rotation of the anisole

What do you think?

[Archer]

Polarimetry is not necessary here, none of your compounds are chiral.

Could distillation remove anethole from fluorenone, using a sand vigreux column. What are the boiling points of anethole and fluorenone?

[heyjude_]

Anisole is around 150 C and fluorenone is over 300, wouldnt that mean i dont need a column?

[Archer]

I would always use a column under these circumstances, provided I have enough sample as you will always loose some you have 10ml so plenty to play with provided your column isn't 2 metres tall!

Columns help to prevent contamination of your distillate product if there is any aerosol formation while your substance is boiling. Also it helps to prevent any contamination if your mixture bumps while is it distilling.

I would use different aparatus to what you have been give access to for this type of distillation (hi vacuum, short path such as a Kugelrohr)