[Lou Lou]

Hi i am just trying to complete a chemistry write up and am being asked why sodium carbonate was added in the preparation of the above.

I am thinking that it is was to neutralise the acid in some way please can someone help me understand this a little better as my books and the internet are only confusing me more.

Sorry if i seem really clueless its probably cos i am 

Thank you

Lou Lou

[sjb]

Could be any number of reasons - how did you make it?

[Lou Lou]

Weigh out potassium bromide (32g) into a round bottomed flask and add 23 cm3 of butan-1-ol. Add concentrated sulphuric acid (12.5 cm3).

Add 6-7 anti-bumping granules and reflux for 30 minutes.

Rearrange the set-up for distillation and warm gently until no more distillation occurs.

Pour the distillate into a separating funnel and add 10% aqueous sodium carbonate solution (75 cm3), swirling the separating funnel during the addition. Shake gently, RELEASING THE PRESSURE BUILD-UP FROM CO2 EVOLUTION FREQUENTLY.

Collect the lower organic layer. Return the organic layer to the separating funnel and add water (50 cm3). Shake gently and then transfer the lower organic layer to a CLEAN, DRY conical flask.

Dry the product using magnesium sulphate.

[MrOHBrown]

I believe that the NaCo₃ solution is used to remove unreacted KBr, H₂SO₄²- and alkanol.

1-Bromobutane is polar, however I am guessing that ions attract more readily with water, and so the addition of solution, and the subsequent wat,er is to remove those ions.

And, carbonate is added, most probably, to neutralise.

I could be totally wrong, any ideas?