Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Chemistry Paper 2 > C12: Chemical Analysis > Flashcards

C12: Chemical Analysis Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

What is a pure substance in chemistry?

A

A single element or compound, not mixed with any other substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What can be used to distinguish pure substances from mixtures?

A

Melting and boiling points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a pure substance in everyday language?

A

A substance that has had nothing added to it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a formulation?

A

A mixture that has been designed as a useful product

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How are formulations made?

A

By mixing the components in carefully measure quantities to ensure that the product has the required properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What 7 things to formulations include?

A

Fuels, cleaning agents, paints, medicine, alloys, fertilisers and food

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Give 2 reasons why chromatography is useful

A

It can separate mixtures and can give information to help identify substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the separation of mixtures depend on?

A

The distribution of substances between the phases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the Rf value in words?

A

The ratio of the distance moved by a compound to the distance moved by a solvent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the formula for the Rf value?

A

Distance by substance/distance by solvent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How can you identify a pure substance using paper chromatography?

A

If it produces a single spot in all solvents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the test for hydrogen?

A

The use of a burning splint held at the open end of the test tube of the gas. Hydrogen burns rapidly with a squeaky pop sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the test for oxygen?

A

The use of a glowing splint is inserted into a test tube of gas. The splint relights in oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the test for carbon dioxide?

A

The use of an aqueous solution of calcium hydroxide (limewater). When carbon dioxide is shaken with or bubbled through limewater, the limewater turns milky

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the test for chlorine?

A

The use of damp litmus paper being put into chlorine gas. It is bleached and turns white

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are flame tests used for?

A

To identify some metal ions (cations)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What colour is the flame when lithium compound is used?

A

Crimson red

18
Q

What compound produces a yellow flame?

A

Sodium

19
Q

What colour is the flame when calcium compound is used?

A

Orange-red

20
Q

What compound produces a lilac flame?

A

Potassium

21
Q

What colour is the flame when copper compound is used?

A

Green

22
Q

What elements in sodium hydroxide form a white precipitate?

A

Aluminium, calcium and magnesium

23
Q

What happens to aluminium hydroxide in excess sodium hydroxide?

A

The precipitate dissolves

24
Q

What colour is the copper(II) precipitate when sodium hydroxide is added in excess?

A

Blue

25
Q

What element forms a green precipitate when sodium hydroxide is added in excess?

A

Iron (II)

26
Q

What colour is the iron (III) precipitate when sodium hydroxide is added in excess?

A

Brown

27
Q

What 2 things react to form a salt, carbon dioxide gas and water?

A

Carbonates and dilute acids

28
Q

What is the test for carbonate ions?

A

Add dilute hydrochloric acid and take gas produced. Run through limewater to observe carbon dioxide production

29
Q

What is the test for sulfate ions?

A

Adding dilute hydrochloric acid, removing carbonate and sulfite ions. Add barium chloride solution to produce a white precipitate

30
Q

What is the test for halide ions?

A

Add dilute nitric acid to remove impurities. Add silver nitrate afterwards so that the silver can react with the halide ions, producing a precipitate

31
Q

What colour is the precipitate from silver chloride?

A

White

32
Q

What compound’s precipitate is cream?

A

Silver bromide

33
Q

What colour is the precipitate from silver iodide?

A

Yellow

34
Q

In paper chromatography, how would you know if any of the chemicals are soluble in the solvent?

A

Then they won’t be able to dissolve and move up the paper

35
Q

What is the mobile phase?

A

The solvent used

36
Q

What is the stationary phase?

A

The paper

37
Q

How do impurities affect melting and boiling points?

A

They decrease MP but increase BP

38
Q

What is the main advantage of flame emission spectroscopy?

A

The line spectrum shows lines for all elements of a compound

39
Q

What are advantages of manual methods, i.e. flame tests?

A

Basic and cheap

40
Q

What are advantages of instrumental methods?

A

Accurate, sensitive and very fast

Chemistry Paper 2 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions