lesson 5 fractional distillation

Question 1

in fractional distillation what do we do

Answer 1

separate a mixture of different liquids

Question 2

in fractional distillation, the liquid must have different what

Answer 2

boiling points

Question 3

in our flask what do we have

Answer 3

a mixture of two different liquids

Question 4

fractional distillation works as well with how many different liquids in the flask

Answer 4

several different liquids

as long as they have different boiling points, fractional distillation will work

Question 5

the flask containing our liquid is attached to what

Answer 5

a long column containing hundreds of glass beads

Question 6

what’s the name of the long column

Answer 6

the fractionating column

Question 7

at the top of the fractionating column, we have what

Answer 7

a thermometer

Question 8

we also have a ________ just like simple distillation

Answer 8

condenser

Question 9

what does cold tap water do around the condenser

Answer 9

circulate

Question 10

what do we do at the start of fractional distillation (after set up) with two different boiling points

Answer 10

we start by gently heating our mixture

Question 11

once you gently heat your mixture, what happens

Answer 11

both our liquids will start to evaporate

Question 12

the liquid with the lower boiling point does what

Answer 12

evaporates more easily

Question 13

once you evaporate your liquids what do we have

Answer 13

a mixture of two different vapours, making their way into the fractionating column

Question 14

when the vapours reach the fractionating column, what occurs

Answer 14

they condense and drip back into the flask where the liquids evaporate again

Question 15

the repeated evaporation and condensation does what

Answer 15

increases the amount of the lower boiling point chemical in the fractionating column

Question 16

as the warm vapours pass up the column, they reach the

Answer 16

thermometer and the temperature of the thermometer begins to rise

Question 17

when the temperature is rising, this means that

Answer 17

a mixture of the two different vapours is passing over the thermometer

Question 18

the mixture that is passing over the thermometer will contain what

Answer 18

more of the chemical with a lower boiling point

Question 19

after the vapours pass over the thermometer they now pass into the

Answer 19

condenser

Question 20

once the vapours pass through the condenser, it turns back into a

Answer 20

liquid

Question 21

once the vapours condenses into a liquid, the liquid is still a mixture of what

Answer 21

the two chemicals

Question 22

there comes a point when the temperature on the thermometer stops rising which will be the what…

Answer 22

the lower of the two boiling points

Question 23

at the point of the temperature of the lower of the two boiling points stops rising on the thermometer, what occurs

Answer 23

we only now mainly have one chemical passing into the condenser

Question 24

as the chemical condenses what can we do with it

Answer 24

collect it in a fresh beaker and that is our first proper fraction

Question 25

after a while of our first proper fraction, what occurs

Answer 25

the temperature starts to rise again

Question 26

the temperature rising again awhile after our first proper fraction means what

Answer 26

a mixture of vapours is passing into the condenser

Question 27

once a mixture of vapours is passing into the condenser awhile after our first proper fraction, the mixture mainly contains what

Answer 27

the chemical with the higher boiling point

Question 28

when the thermometer reaches a constant temperature what do we collect

Answer 28

a relatively pure sample of the second chemical

Question 29

if the two liquids have very similar boiling points, what does this mean

Answer 29

that is is much harder to separate and may need to carry several rounds of fraction distillation