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Flashcards in Acids And Bases Deck (41):
1

What is the pH scale

A measure of how acidic or alkaline a solution is

2

What is a neutral substance on the pH scale

pH 7

3

What is an acid

A substance with a pH of less than 7.

4

What do acids form in water

H+ ions

5

What is a base

A substance that reacts with an acid to produce salt and watee

6

What is an alkali

A base that is soluble in water. They have a pH of more than 7

7

What do alkalis form in water

OH- ions

8

What is an indicator

A dye that changes colour depending on whether it’s above or below a certain pH

9

What are the colours of litmus

Red in acidic solutions
Purple in neutral
Blue in alkaline

10

What is the colour of methyl orange when reacting with acids and alkalis

Red in acidic solutions
Yellow in neutral
Yellow in alkaline

11

What is the colour of phenolphthalein when reacting with acids and alkalis

Colourless in acidic solutions
Colourless in neutral
Pink in alkaline

12

What is neutralisation

The reaction between an acid and a base

13

What does neutralisation produce

Salt and water

14

What can acids do in a solution

Ionise

15

What are the properties of strong acids

Ionise almost completely in water
Low pHs

16

What are the properties of weak acids

Do not fully ionise in solution
pH around 2-6

17

What is the ionisation of a weak acid

A reversible reaction

18

What does acid strength tell you

What proportion of the acid molecules ionise in water

19

What does the concentration of acid tell you

How much acid there is in a litre

20

What makes a concentrated acid

An acid with a large number of acid molecules compared to volume of water

21

What makes a dilute acid

A small number of acid particles compared to volume of water

22

What kind of reaction does salt form in

A neutralisation reaction

23

What kind of compounds are salts

Ionic compounds

24

What salts does hydrochloric acid produce

Chloride salts

25

What kind of salts does sulfuric acid produce

Sulfate salts

26

What kind of salts does nitric acid produce

Nitrate salts

27

Acid + metal oxide —> ?

Salt + water

28

Acid + metal hydroxide —>

Salt + water

29

Acid + metal —> ?

Salt + hydrogen

30

Acid + metal carbonate —> ?

Salt + water + carbon dioxide

31

What is the test for hydrogen

Hydrogen makes a ‘squeaky pop’ with a lighted splint

32

What is the test for carbon dioxide

Bubbling it through limewater. Limewater will turn cloudy

33

What is electrolysis

The breaking down of a substance using electricity

34

What is oxidation

Loss of electrons

35

What is reduction

Gain of electrons

36

What do half equations show

How electrons are transferred during reactions

37

What is an electrochemical cell

A circuit made up of the anode, cathode, electrolyte, a power source and the wires that connect the two electrodes

38

Can an ionic solid be electrolysed, why

No because the ions are in fixed positions and can’t move

39

Can molten ionic compounds be electrolysed, why

Yes because the ions can move freely and conduct electricity

40

What happens to positive metal ions during electrolysis

They are reduced to metal atoms at the cathode

41

What happens to negative ions during electrolysis

They are oxidised to atoms or compounds at the anode