Acids And Bases

Question 1

What is the pH scale

Answer 1

A measure of how acidic or alkaline a solution is

Question 2

What is a neutral substance on the pH scale

Answer 2

pH 7

Question 3

What is an acid

Answer 3

A substance with a pH of less than 7.

Question 4

What do acids form in water

Answer 4

H+ ions

Question 5

What is a base

Answer 5

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

Question 6

What is an alkali

Answer 6

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

Question 7

What do alkalis form in water

Answer 7

OH- ions

Question 8

What is an indicator

Answer 8

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

Question 9

What are the colours of litmus

Answer 9

Red in acidic solutions
Purple in neutral
Blue in alkaline

Question 10

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

Answer 10

Red in acidic solutions
Yellow in neutral
Yellow in alkaline

Question 11

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

Answer 11

Colourless in acidic solutions
Colourless in neutral
Pink in alkaline

Question 12

What is neutralisation

Answer 12

The reaction between an acid and a base

Question 13

What does neutralisation produce

Answer 13

Salt and water

Question 14

What can acids do in a solution

Answer 14

Ionise

Question 15

What are the properties of strong acids

Answer 15

Ionise almost completely in water

Low pHs

Question 16

What are the properties of weak acids

Answer 16

Do not fully ionise in solution

pH around 2-6

Question 17

What is the ionisation of a weak acid

Answer 17

A reversible reaction

Question 18

What does acid strength tell you

Answer 18

What proportion of the acid molecules ionise in water

Question 19

What does the concentration of acid tell you

Answer 19

How much acid there is in a litre

Question 20

What makes a concentrated acid

Answer 20

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

Question 21

What makes a dilute acid

Answer 21

A small number of acid particles compared to volume of water

Question 22

What kind of reaction does salt form in

Answer 22

A neutralisation reaction

Question 23

What kind of compounds are salts

Answer 23

Ionic compounds

Question 24

What salts does hydrochloric acid produce

Answer 24

Chloride salts

Question 25

What kind of salts does sulfuric acid produce

Answer 25

Sulfate salts

Question 26

What kind of salts does nitric acid produce

Answer 26

Nitrate salts

Question 27

Acid + metal oxide —> ?

Answer 27

Salt + water

Question 28

Acid + metal hydroxide —>

Answer 28

Salt + water

Question 29

Acid + metal —> ?

Answer 29

Salt + hydrogen

Question 30

Acid + metal carbonate —> ?

Answer 30

Salt + water + carbon dioxide

Question 31

What is the test for hydrogen

Answer 31

Hydrogen makes a ‘squeaky pop’ with a lighted splint

Question 32

What is the test for carbon dioxide

Answer 32

Bubbling it through limewater. Limewater will turn cloudy

Question 33

What is electrolysis

Answer 33

The breaking down of a substance using electricity

Question 34

What is oxidation

Answer 34

Loss of electrons

Question 35

What is reduction

Answer 35

Gain of electrons

Question 36

What do half equations show

Answer 36

How electrons are transferred during reactions

Question 37

What is an electrochemical cell

Answer 37

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

Question 38

Can an ionic solid be electrolysed, why

Answer 38

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

Question 39

Can molten ionic compounds be electrolysed, why

Answer 39

Yes because the ions can move freely and conduct electricity

Question 40

What happens to positive metal ions during electrolysis

Answer 40

They are reduced to metal atoms at the cathode

Question 41

What happens to negative ions during electrolysis

Answer 41

They are oxidised to atoms or compounds at the anode