Topic 2 - States of Matter and Mixtures Flashcards Preview

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Flashcards in Topic 2 - States of Matter and Mixtures Deck (24):
1

Pure substance

One single element or compound

2

Testing purity

Comparing melting points with expected and actual. Also if the MP is a specific point not a range.

3

Simple distillation

Separating liquid from solution.

4

Limitation of simple distillation

The 2 components must have very different boiling points. If not fractional distillation is used.

5

Fractional distillation use

Mixture of liquids

6

Filtration

Separating an insoluble salt from liquid

7

Crystallisation

Separating a soluble salt

8

Chromatography

Separate a mixture of soluble substances

9

Mobile phase

Where molecules can - water (solvent)

10

Stationary phase

Where molecules can’t move, paper

11

Why pencil is used in chromatography

It’s insoluble so won’t move.

12

If a spot on chromatography doesn’t move

Insoluble

13

Why chemicals move up chromatography paper.

They dissolve in water and are taken with it up the paper.

14

Time taken for chromatography (how far)

How soluble
How attracted to stationary phase

15

Colourless chemicals on chromatogram

Spray with locating agent

16

Rf Value

Distance travelled by solute(chemical)
Distance travelled by mobile phase (water)

17

SRM and Chromotography

Standard reference materials, used to compare and identify a substance.

18

Purity test using chromatography

If there is only 1 spot it’s pure.

19

Sources of UK water

Surface water - lakes, rivers, reservoirs

Ground water - aquifers (rocks trap water underground)

Waste water - from contaminated water from industry

20

Filtration from water treatment

Wire mesh screens out twigs, gravel, sand

21

Sedimentation

Iron or aluminium sulfate are added to water to make fine particles clump together

22

Chlorination and water treatment

Cl2 is bubbles through to kill bacteria or microbes.

23

Distillation and water treatment

In dry countries water is distilled. It requires lots of energy for high amounts.

24

Use of deionised water (distilled)

Ions are removed which could interfere with reactions.