C1.4 - R* Fractional distillation and paper chromatography

Question 1

What can fractional distillation be used for?

Answer 1

Fractional distillation can be used to separate mixtures of miscible liquids

Question 2

Miscible describes liquids that what?

Answer 2

Miscible describes liquids that:

1. Dissolve in each other, mixing completely
2. Do not form the separate layers seen in mixtures of immiscible liquids that have been allowed to settle

Question 3

Miscible liquids will have what?

Answer 3

Miscible liquids will have different boiling points

Question 4

Why is it difficult to get pure liquids from mixtures of liquids with similar boiling points by simple distillation?

Answer 4

It is difficult to get pure liquids from mixtures of liquids with similar boiling points by simple distillation, because vapour is given off from each liquid before they actually reach their boiling point

Question 5

Fractionating column

Answer 5

A fractionating column is usually a tall glass column filled with glass beads

Question 6

In fractional distillation, what must the vapours do?

Answer 6

In fractional distillation, the vapours must pass:
1. Over
2. Between
the glass beads in the fractionating column before they reach the condenser

Question 7

The temperature of the fractionating column is what at the bottom of the column?

Answer 7

The temperature of the fractionating column is highest at the bottom of the column

Question 8

What does the temperature of the fractionating column mean that the substance with the higher boiling point will do?

Answer 8

The temperature of the fractionating column means that the substance with the higher boiling point will:

1. Condense more readily on the cooler glass beads nearer the bottom of the column
2. Drip back down into the flask beneath

Question 9

What does the temperature of the fractionating column mean that the substance with the lower boiling point will do?

Answer 9

The temperature of the fractionating column means that the substance with the lower boiling point will:

1. Continue rising
2. Pass over into the condenser

Question 10

Boiling point of ethanol

Answer 10

The boiling point of ethanol is 78 degrees Celsius

Question 11

Boiling point of water

Answer 11

The boiling point of water is around 100 degrees Celsius

Question 12

When using fractional distillation to separate a mixture of ethanol and water, if the temperature reading on the thermometer can be kept at around 80 degrees Celsius, what will the liquid collected be?

Answer 12

When using fractional distillation to separate a mixture of:
1. Ethanol
2. Water
,if the temperature reading on the thermometer can be kept at around 80 degrees Celsius, the liquid collected will be mainly ethanol

Question 13

How can you test the difference between the starting mixture of ethanol and water and the distillate collected?

Answer 13

You can test the difference between the:
1. Starting mixture of ethanol and water
2. Distillate collected
by applying a lighted splint to a small volume of each (the starting mixture of ethanol and water and the distillate collected) in an evaporating dish

Question 14

Ethanol is relation to flammability

Answer 14

Ethanol is a flammable liquid, but it is not flammable when mixed with an excess of water

Question 15

In the fractional distillation of ethanol and water, the distillate collected in relation to flammability

Answer 15

In the fractional distillation of ethanol and water, the distillate will ignite when a flame is applied

Question 16

In the fractional distillation of ethanol and water, how does the distillate collected burn?

Answer 16

In the fractional distillation of ethanol and water, the distillate collected burns with a clear blue flame

Question 17

Why is fractional distillation used in the alcoholic spirits industry?

Answer 17

Factional distillation is used in the alcoholic spirits industry to separate ethanol from a fermented mixture

Question 18

Fractional distillation is used in the use of ethanol as a what?

Answer 18

Fractional distillation is used in the use of ethanol as a biofuel

Question 19

Biofuel

Answer 19

A biofuel is a fuel made from:
1. Animal
Or,
2. Plant
products

Question 20

Why does chromatography work?

Answer 20

Chromatography works, because some compounds in a mixture will dissolve better than others in the solvent chosen

Question 21

What determines how far up the components making up a mixture travel up the absorbent chromatography paper?

Answer 21

The relative solubility determines how far up the components making up a mixture travel up the absorbent chromatography paper

Question 22

In chromatography, what happens the more soluble a substance is in the solvent?

Answer 22

The more soluble a substance is in the solvent, the further up the paper it is carried

Question 23

What will each different dye/pigment in the solution do in paper chromatography?

Answer 23

Each different dye/pigment in the solution in paper chromatography will move up the sheet at a different rate

Question 24

In paper chromatography, what will happen if any of the dyes in the ink are insoluble (won’t dissolve) in the solvent you’ve used?

Answer 24

In paper chromatography, if any of the dyes in the ink are insoluble (won’t dissolve) in the solvent you’ve used, they’ll stay on the baseline

Question 25

What is paper chromatography a really useful technique to do?

Answer 25

Paper chromatography is a really useful technique to separate compounds out of a mixture

Question 26

What can chromatography be used to separate?

Answer 26

Chromatography can be used to separate different dyes in an ink

Question 27

Why should you make sure you use a pencil to draw your baseline on the sheet of paper for your chromatogram and in the 1st step of paper chromatography?

Answer 27

You should make sure you use a pencil to draw your baseline on the sheet of paper for your chromatogram and in the 1st step of paper chromatography, because: 1. Pencil marks are insoluble and won't dissolve in the solvent 2. If you use pen, all the components of the ink in the pen will get separated, along with the substance you're analysing

Question 28

Another type of distillation other than simple distillation

Answer 28

Another type of distillation other than simple distillation is fractional distillation

Question 29

Fractional distillation is more what to carry out than simple distillation?

Answer 29

Fractional distillation is more complicated to carry out than simple distillation

Question 30

Where is fractional distillation used?

Answer 30

Fractional distillation is used in: 1. The lab 2. Industry

Question 31

It is difficult to get pure liquids from mixtures of liquids with similar boiling points by simple distillation, because vapour is given off from each liquid before they actually reach their boiling point, so what can you do to aid separation?

Answer 31

It is difficult to get pure liquids from mixtures of liquids with similar boiling points by simple distillation, because vapour is given off from each liquid before they actually reach their boiling point, so to aid separation you can add a fractionating column to the apparatus for distillation

Question 32

Miscible liquids will have different boiling points, so you can use this to do what?

Answer 32

Miscible liquids will have different boiling points, so you can use this to: 1. Distil off 2. Collect the liquid with the lowest boiling point first

Question 33

The more soluble a substance is in the solvent, the further up the paper it is carried, so what can be used in chromatography to maximise separation?

Answer 33

The more soluble a substance is in the solvent, the further up the paper it is carried, so different solvents can be used in chromatography to maximise separation

Question 34

Each different dye/pigment in the solution will move up the sheet at a different rate, so they will separate out. What will each dye/pigment do?

Answer 34

Each dye/pigment will form a spot in a different place

Question 35

Fractional distillation can be used to separate mixtures of miscible liquids, such as what?

Answer 35

Fractional distillation can be used to separate mixtures of miscible liquids, such as: 1. Ethanol 2. Water

Question 36

Miscible describes liquids that dissolve in each other, mixing completely and do not form the separate layers seen in mixtures of immiscible liquids that have been allowed to settle, such as what?

Answer 36

Miscible describes liquids that dissolve in each other, mixing completely and do not form the separate layers seen in mixtures of immiscible liquids that have been allowed to settle, such as the: 1. Oil 2. Water layers in a salad dressing

Question 37

A fractionating column is usually a tall glass column filled with glass beads, fitted where?

Answer 37

A fractionating column is usually a tall glass column filled with glass beads, fitted vertically on top of the flask being heated

Question 38

The temperature of the fractionating column is highest at the bottom of the column, getting lower as what?

Answer 38

The temperature of the fractionating column is highest at the bottom of the column, getting lower as the vapours rise up

Question 39

The temperature of the fractionating column means that the substance with the lower boiling point will continue rising and pass over into the condenser, where it is what?

Answer 39

The temperature of the fractionating column means that the substance with the lower boiling point will continue rising and pass over into the condenser, where it is cool enough to: 1. Turn back into the liquid state 2. Be collected

Question 40

In the fractional distillation of ethanol and water, the distillate will ignite when a flame is applied, because what?

Answer 40

In the fractional distillation of ethanol and water, the distillate will ignite when a flame is applied, because the ethanol collected should only have a small amount of water present

Question 41

In the fractional distillation of ethanol and water, the distillate collected burns with a clear blue flame, just like the flame when what is lit?

Answer 41

In the fractional distillation of ethanol and water, the distillate collected burns with a clear blue flame just like the flame when the brandy on a Christmas pudding is lit

Question 42

Each different dye/pigment in the solution in paper chromatography will move up the sheet at a different rate, so they will what?

Answer 42

Each different dye/pigment in the solution in paper chromatography will move up the sheet at a different rate, so they will separate out

Question 43

You should make sure you use a pencil to draw your baseline on the sheet of paper for your chromatogram and in the 1st step of paper chromatography, because pencil marks are insoluble and won't dissolve in the solvent and if you use pen, all the components of the ink in the pen will get separated, along with the substance you're analysing, which will do what?

Answer 43

You should make sure you use a pencil to draw your baseline on the sheet of paper for your chromatogram and in the 1st step of paper chromatography, because: 1. Pencil marks are insoluble and won't dissolve in the solvent 2. If you use pen, all the components of the ink in the pen will get separated, along with the substance you're analysing, which will make your results very confusing

Question 44

Fractional distillation is more complicated to carry out than simple distillation, but it can do what?

Answer 44

Fractional distillation is more complicated to carry out than simple distillation, but it can separate out mixtures of liquids even if their boiling points are close together

Question 45

Each different dye/pigment in the solution will move up the sheet at a different rate, so they will separate out. Each dye/pigment will form a spot in a different place. What will there be per dye/pigment in the mixture?

Answer 45

There will be 1 spot per dye/pigment in the mixture