Using Resources- 10

Question 1

What is a pure substance

Answer 1

A substance, either element or compound, that is not mixed with any other substance

Question 2

Pure substances have…

Answer 2

Specific melting and boiling points

Question 3

What does paper chromatography do?

Answer 3

It allows us to separate substances based on their different solubilities

Question 4

Chromatography paper set up

Answer 4

Draw line in pencil on the paper (stationary phase)- dot of colour goes on the line. Put the paper in a solvent (mobile phase) under the line (not submerging the dots.

Question 5

What will pure compounds form in paper chromatography

Answer 5

One single spot

Question 6

What will compounds in a mixture form in paper chromatography

Answer 6

Multiple spots

Question 7

Why do you draw the line in pencil?

Answer 7

So that the ink doesn’t also move up the page

Question 8

How to find Rf Values paper chromatography?

Answer 8

distance moved by substance/distance moved by solvent

Question 9

How to test for hydrogen

Answer 9

We insert a burning splint when the hydrogen gas burns and produces a pop sound

Question 10

How to test for oxygen

Answer 10

Glowing splint will relight

Question 11

How to test for carbon dioxide

Answer 11

Bubble through limewater (aqueous calcium hydroxide) and turns cloudy

Question 12

How to test for chlorine

Answer 12

Insert damp litmus paper into the test tube, and bleaches it

Question 13

What flame does lithium ion produce

Answer 13

Crimson

Question 14

What flame does sodium ion produce

Answer 14

Yellow

Question 15

What flame does potassium ion produce

Answer 15

Lilac

Question 16

What flame does calcium ion produce

Answer 16

Orange-red

Question 17

What flame does copper ion produce

Answer 17

Green

Question 18

What colour precipitate do calcium, magnesium and aluminium form when combined with sodium hydroxide

Answer 18

White

Question 19

How do you work out which white precipitate is aluminium?

Answer 19

Add an excess of NaOH

Question 20

What colour do copper 2+ ions turn when reacted with sodium hydroxide

Answer 20

Blue- copper (II) hydroxide

Question 21

What colour do Iron 2+ ions turn when reacted with sodium hydroxide

Answer 21

Green- iron (II) hydroxide

Question 22

What colour do Iron 3+ ions turn when reacted with sodium hydroxide

Answer 22

Brown-red- Iron (III) hydroxide

Question 23

How to test for a carbonate ion

Answer 23

Add dilute acid to the sample
The acid will react with the carbonate to make CO2 gas
Bubble the gas through limewater to make sure that we have carbon dioxide and therefore started with a carbonate ion

Question 23

How to test for halide ions

Answer 23

Add dilute nitric acid
Then add dilute silver nitrate solution
Halides each produce a precipitate of the silver halide

Question 24

What colour do chloride ions produce?

Answer 24

White- silver chloride

Question 25

What colour precipitate do bromide ions produce?

Answer 25

Cream- silver bromide

Question 26

What colour precipitate do iodide ions produce?

Answer 26

Yellow- silver iodide

Question 27

How to test for sulfate ions

Answer 27

Add dilute HCL to our sample Add barium chloride solution If sulfate ions are present, we will see a white precipitate

Question 28

What is the solvent front in chromatography

Answer 28

The top of the solvent

Question 29

What is potable water

Answer 29

Water that's safe to drink

Question 30

Criteria for potable water

Answer 30

Level of dissolved substances need to be fairly low pH between 6.5-8.5 No microorganisms in it

Question 31

How to make water potable

Answer 31

Fresh water passed through wire mesh to remove big things Bed of sand and gravel to filter out smaller bits Sterilise by bubbling chlorine gas through/using ozone or UV light

Question 32

How to desalinate water

Answer 32

Use distillation to get pure distilled water Reverse osmosis- pass salty water through a membrane that only lets water molecules through

Question 33

Sources of wastewater

Answer 33

Domestic Agricultural systems Industrial

Question 34

How to treat sewage

Answer 34

Run through mesh to remove large objects 'Sedimentation' allows for sludge to sink to the bottom and the lighter effluent to stay at the top Breakdown organic matter biologically by microorganisms