Separate Chemistry 2

Question 1

What colour will lithium go in a flame test?

Answer 1

Red (crimson)

Question 2

What colour will sodium go in a flame test?

Answer 2

Yellow

Question 3

What colour will potassium go in a flame test?

Answer 3

Lilac

Question 4

What colour will Calcium go in a flame test?

Answer 4

Orange-red

Question 5

What colour will Copper go in a flame test?

Answer 5

blue-green

Question 6

What colour will Aluminium go in the precipitate test?

Answer 6

White at first, but redissolves in excess NaOH to form a colourless solution.

Question 7

What colour will Calcium go in the precipitate test?

Answer 7

White

Question 8

What colour will Copper go in the precipitate test?

Answer 8

Blue

Question 9

What colour will Iron 2+ go in the precipitate test?

Answer 9

Green

Question 10

What colour will Iron 3+ go in the precipitate test?

Answer 10

Brown

Question 11

How can you test for ammonium ions?

Answer 11

Add NaOH and gently heat. Hold a piece of damp red litmus and if it is ammonia, it will turn blue.

Question 12

What do you add to test for halide ions?

Answer 12

Silver Nitrate and nitric acid

Question 13

What colour will chloride ions go when silver nitrate is added?

Answer 13

Gives a white precipitate of silver chloride

Question 14

What colour will bromide ions go when silver nitrate is added?

Answer 14

Gives a cream precipitate of silver bromide

Question 15

What colour will iodide ions go when silver nitrate is added?

Answer 15

Gives a yellow precipitate of silver iodide

Question 16

How do you test for carbonate ions?

Answer 16

Add dilute acid, if it fizzes, it is a carbonate.

Question 17

How do you test for sulfate ions?

Answer 17

Add dilute HCl then add barium chloride. If a white precipitate of barium sulfate if formed, it is a sulfate ion.

Question 18

What is flame photometry?

Answer 18

An instrumental method that allows you to identify ions in a dilute solution.

Question 19

Give 3 advantages of using machines to analyse unknown substances.

Answer 19

Very sensitive, very fast, very accurate.

Question 20

How big are nanoparticles?

Answer 20

1-100nm

Question 21

Are nanoparticles bigger or smaller than atoms?

Answer 21

Bigger, nanoparticles typically contain about 100 atoms.

Question 22

Do nanoparticles have a high or low surface area to volume ratio?

Answer 22

High

Question 23

Give some uses of nanoparticles.

Answer 23

Catalysts, cosmetics, nanomedicine, lubrication, electric circuits, sports equipment and wound dressings (silver nanoparticles)

Question 24

Why could nanoparticles be dangerous?

Answer 24

Some nanoparticles used in medicine don’t break down easily so they could start to build up in cells, could cause lung inflammation if breathed in.

Question 25

Give 2 properties of ceramics.

Answer 25

Stiff but brittle

Question 26

What is clay and what are its properties?

Answer 26

A mineral formed from weathed rock. It is soft when dug up which makes it easy to mould. Can be hardened at high temperatures making It ideal for building.

Question 27

What is glass and what are its properties?

Answer 27

Generally transparent and strong and can be moulded when hot. Most glass is soda-lime glass which is made by heating limestone, sand and sodium carbonate.

Question 28

Give 2 examples of composite materials.

Answer 28

Fibreglass and concrete.

Question 29

How is carbon fibre made?

Answer 29

Carbon atoms are bonded together to make carbon fibres or carbon nanotubes held together in a polymer resin.