Organic Chemistry

Question 1

Heat under reflux - why?

Answer 1

heat to speed up reaction without losing reactants or products

Question 2

Heat under reflux - how?

Answer 2

• condenser is filled with water to ensure effective cooling
• vapours given off during liquid reaction change from gas back to liquid due to heat loss
• this causes the liquid to fall back into the round bottom flask = higher yield

Question 3

Distillation - why?

Answer 3

used to separate/purify the product from any remaining reactants

Question 4

Distillation - how?

Answer 4

• condenser is filled with water to ensure effective cooling
• organic molecules in the impure mixture have different boiling points
• the liquid with the lower b.p. will start to boil at the lower temp, evaporate and move down the condenser where it is cooled and returns to the liquid state

Question 5

Separating funnel - why?

Answer 5

allows two reactants to be shaken together and for compounds to be separated based on their solubility

Question 6

Separating funnel - how?

Answer 6

• e.g. an ester/haloalkane is not soluble in water and will not mix with the aqueous layer
• the more dense liquid will be in the lower level and can be run off by removing the stopper and opening the tap
• the less dense layer is poured off through the top of the separating funnel

Question 7

How can two enantiomers be distinguished?

Answer 7

they rotate plane-polarised light in opposite directions (one left. one right)