Brainscape's Knowledge GenomeTM

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


See full index

AQA Chemistry GCSE > Topic 4 - Chemical Changes > Flashcards

Topic 4 - Chemical Changes Flashcards

You may prefer our related Brainscape-certified flashcards:
GCSE Geography - AQA flashcards AP® Chemistry flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route A flashcards GCSE Religious Studies - Edexcel Route A flashcards GCSE Religious Studies - Eduqas Route B flashcards Periodic Table flashcards Chemistry 101 flashcards Organic Chemistry 101 flashcards
1
Q

What does the pH scale measure?

A

How acidic or alkali something is

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

What is the pH of an acid

A

0-6

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

What is the pH of an alkali?

A

8-14

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

What does an acid form in water?

A

H+ ions

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

What does an alkali produce in water?

A

OH- ions

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

What is the name of the reaction between an acid and a base?

A

Neutralisation

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

What is the word and symbol equation for neutralisation?

A

Acid + Base -> Salt + Water

H+ + OH- -> H20

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

When adding strong and weak acids to water, what is the difference?

A

Strong acid ionise completely making lots of H+ ions but Weak Acids don’t fully ionise making less H+ ions

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

Why is the pH different in strong and weak acids?

A

Strong acids have more H+ ions

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

What concentration does the pH scale measure?

A

The concentration of H+ ions

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

What is the relationship tween an increased of H+ ions and a decrease in a pH by 1?

A

For every decrease of 1 in the scale the conc of H+ ions increases by a factor of 1

E.g. an acid of pH 4 has 10 times more H+ ions then an acid of pH5

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

Can metal oxides and metal hydroxides dissolve in water?

A

Yes. Some metal oxides and metal hydroxides dissolve in water

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

What is the word equation for a metal oxide/hydroxide being added to acid?

A

Acid + metal oxide/metal hydroxide -> salt + water

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

Are metal oxides and hydroxides acid or alkali and how do we know?

A

They are alkali and we know because the form a salt and water when dropped in acid. The neutralise

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

What is the word equation for a metal carbonate dropped into acid?

A

Acid + metal carbonate -> Salt + Water + Carbon Dioxide

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

What does oxidation and reduction mean?

A

Oxidisation - a gain in oxygen or loss of electrons
Reduction - a loss in oxygen or gain of electrons

17
Q

What is a redox reaction?

A

A reaction where reduction and oxidisation is happening simultaneously

18
Q

What is a displacement reaction?

A

A more reactive metal will displace a less reactive metal from its compound. They are redox reactions

19
Q

Give a word and symbol equation as an example of a displacement reaction

A

Iron + copper sulphate -> copper + iron sulphate
Fe + CuSo4 -> FeSo4 + Cu

20
Q

What is an ionic equation?

A

An ionic equation is an equation where only the particles that react and the products are shown.

21
Q

What is electrolysis?

A

The process of splitting up an ionic compound with electricity

22
Q

What substances can be electrolysed?

A

Electrolysis works with both molten ionic solids and aqueous solutions

23
Q

Why can’t an ionic solid be electrolysed?

A

It’s ions are not free to flow

24
Q

When electrolysing molten solids, what forms at the anode?

A

Non metal ions are oxidised (lose electrons)

25
Q

When electrolysing molten solids, what forms at the cathode?

A

Positive metal ions - they are reduced - gain electrons

26
Q

Which way do ions move in electrolysis?

A

Positive ions move towards the cathode and gain electrons.
Negative ions move toward the anode and lose electrons

27
Q

What electrode is negative and what one is positive?

A

The cathode is negative and the anode in positive

28
Q

When electrolysing aqueous solutions, what forms on the cathode?

A

If H+ ions and metal ions are present, hydrogen gas will be produced if the metal ions form a metal more reactive than hydrogen. If the metal is less reactive than hydrogen the metal will be produced instead

29
Q

When electrolysing aqueous solutions, what forms around the anode?

A

If OH- ions and halide ions are present the halide will be produced, if no halide is present then OH- ions are discharged and oxygen is formed.

30
Q

What are half equations?

A

Half equations are used to show the reactions at both electrodes. Half equations need balanced electrons on both the negative and positive equation.

31
Q

What is the point of a titration?

A

A titration is used to find out exactly how much acid is needed to neutralise a quantity of alkali

32
Q

What indicator is most commonly used for titration?

A

Phenolphthalein

33
Q

What colours is phenolphthalein when acid and alkali?

A

Acid - clear
Alkali - pink

34
Q

What colours is litmus when acid and alkali?

A

Acid - red
Alkali - blue/purple

35
Q

What colour is methyl orange when acid or alkali?

A

Acid - red
Alkali - yellow

36
Q

What is the order of the reactivity series?

A

Potassium, sodium, lithium, calcium, magnesium, carbon, zinc, iron, hydrogen, copper

37
Q

What are the two ways of extracting metals from metal oxides?

A

More reactive than carbon - electrolysis
Less reactive than carbon - reduction my carbon

38
Q

What are some metals more reactive than others?

A

It depends on the metals tendency to form positive ions

39
Q

What is the difference between a sting and weak acid?

A

A strong acid is completely ionised in aqueous solutions whereas a weak acid is only partially ionised

AQA Chemistry GCSE (14 decks)

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