Distillation and organic tests

Question 1

Distillation apparatus

Answer 1

The thermometer with bulb level with condenser
The aldehyde forms and is vaporised and moves upwards
reaction mixture, ethanal and H+
Water out then water in
vapour reaches condenser and is cooled back to a liquid.
Open end to prevent build up of pressure
collect the distillate

Question 2

what happens to the aldehyde as it is produced during distillation

Answer 2

aldehyde boils and vaporizes then escapes from the mixture

Question 3

why is distillation used when producing an aldehyde from a primary alcohol

Answer 3

to prevent further oxidation, the vapour is cooleddown and collected as a distillate

Question 4

ethanol can be oxidized to ethanal- describe how it can be made in high yield as opposed to reflux

Answer 4

heat the mixture to the boiling point of ethanal, set up distillation, maintain the temp at the boiling point of aldehyde so its condensed to a liquid and collected

Question 5

test for aldehydes

Answer 5

tollens test: Tollens reagent, silver mirror forms, no visible change

[Ag(NH3)2]+ + e- –> Ag + 2NH3

Fehlings: Fehlings reagent
brick red ppt, No visible change

Cu2+ + e—> Cu+

Question 6

Test for carboxylic acid

Answer 6

Na2CO3– effervescence

CO32- + 2H+ –> CO2 + H2O