alcohols PMT

Question 1

Q2a Give two reasons why the apparatus shown in above figure is not safe.

Answer 1

flask not clamped
bung in condenser

Question 2

Q2c State two more mistakes in the way the apparatus is set up in above figure.

Answer 2

direction of water flow through condenser
thermometer not needed

Question 3

Q9c Suggest why sodium carbonate solution was used to wash the distillate.

Answer 3

would neutralise the H3PO4 in

Question 4

Q9e Give a property of anhydrous calcium chloride, other than its ability to absorb water, that makes it suitable as a drying agent in this preparation.

Answer 4

Does not dissolve in/react with the cyclohexene

Question 5

Q9f Describe the apparatus used to remove the drying agent by filtration under reduced pressure. Your description of the apparatus can be either a labelled diagram or a description in words.

Answer 5

Buchner funnel containing filter paper Buchner flask connected to vacuum pump

Question 6

Q12a Describe how the students would use this apparatus to collect a sample of ethanol.
Include in your answer the functions of the parts of the apparatus labelled A, B and C.

Answer 6

Stage 1
* Turn on the water.
* Heat the flask, with a Bunsen burner.
* This causes water and ethanol vapours to be produced.
Stage 2
* Vapours pass up the fractionating column A.
* Water and ethanol are separated in column A.
* Water condenses back into the flask in column A.
Stage 3
* Observe the thermometer at B to keep the temperature at or below the boiling point of ethanol.
Only ethanol vapour (with a little water) passes into the condenser.
* Use the condenser at part C to cool the vapours and condense the ethanol back into a liquid.