2.5 - Salts And Electrolysis

Question 1

What is the ionic equation for neutralisation?

Answer 1

H + OH -> H2O

Question 2

What does a pH meter do?

Answer 2

Gives an accurate numerical value for pH

Question 3

What is concentrated and dilute acids/alkalis?

Answer 3

Concentrated- many particles

Dilute - fewer particles

Question 4

What is strong and weak acids/alkalis?

Answer 4

Strong - completely ionises

Weak - partially ionises

Question 5

What does acid + metal produce?

Answer 5

Soluable salt + hydrogen gas

Question 6

What does acid + base(metal oxide) produce?

Answer 6

Soluable salt + water

Question 7

What does acid + metal carbonate produce?

Answer 7

Soluable salt + carbon dioxide + water

Question 8

What does acid + alkali produce?

Answer 8

Soluable salt + water

Question 9

Name the salts for:
Hydrochloric acid
Sulfuric acid
Nitric acid

Answer 9

Chloride salts
Sulfate salts
Nitrate salts

Question 10

Why do you need excessive amounts of metals, bases or carbonates?

Answer 10

To make sure all the acid reacts

Excess solid can be removed by filtration

Question 11

What are ammonium salts used for?

Answer 11

Fertilisers

Question 12

What does soluable salt + soluable salt produce?

Answer 12

Soluable salt + insoluable salt (precipitate)

Question 13

Give an example of two soluable salts reaction

Answer 13

Potassium Iodide + Silver Nitrate -> Potassium Nitrate + Silver Iodide (precipitate)

Question 14

How do you know what the precipitate is in 2 soluable salt reaction?

Answer 14

The least reactive product made

Question 15

What is electrolysis?

Answer 15

The breaking down of an ionic substance into it’s elements using electricity

Question 16

What does the substance have to be for electrolysis to work and why?

Answer 16

It has to be dissolved in water or molten. This is because the ions need to be free to move

Question 17

What does the negatively charged electrode attract?

Answer 17

Positively charged ions (usually metal)

Question 17

What is the negatively charged electrode called?

Answer 17

Cathode

Question 18

What does the positively charged electrode attract?

Answer 18

Negatively charged ions

Question 19

What is the positively charge electrode called?

Answer 19

Anode

Question 21

What happens at the negative electrode?

Answer 21

Reduction which is the gain of electrons

Question 22

What happens at the positive electrode?

Answer 22

Oxidation which is the loss of electron(s)

Question 23

If in a solution what could be produced at the negative electrode?

Answer 23

The positive ion
Metal or Hydrogen
Whichever is the least reactive out of the two

Question 24

If in a solution what could be produced at the positive electrode?

Answer 24

A halide element (group 7) if not then oxygen

Question 25

What is produced in the electrolysis of Brine (Sodium Chloride)

Answer 25

Positive electrode: Chlorine Negative: Hydrogen Left over: Sodium Hydroxide

Question 26

How can you test for hydrogen?

Answer 26

Put a lit split into the gas it should make a squeaky pop

Question 27

How do you test for chlorine?

Answer 27

It bleaches litmus paper

Question 28

What is chlorine, Hydrogen and sodium hydroxide used in

Answer 28

Chlorine: disinfectant, killing bacteria Hydrogen: alternative fuel, margarine Sodium Hydroxide: soap, ceramics, paper, nautralisation

Question 29

Describe extraction of Aluminium Oxide?

Answer 29

Using electrolysis: Insoluable so has to be melted Cryolite added to reduce boiling point from 2700 to 970 This saves energy costs

Question 30

What is produced at each electrode in the extraction of Aluminium?

Answer 30

Positive: oxygen Negative: aluminium

Question 31

If oxygen is produced at the positive electrode in extraction of aluminium oxide what could happen?

Answer 31

As the electrode is made of graphite that is made of carbon The carbon reacts with the oxygen to produce Carbon dioxide The electrodes will burn away and have to be replaced

Question 32

What is electroplating?

Answer 32

Puts a thin coating of metal in an object | To make it more attractive, protect from corrosion or increase hardness

Question 33

Where is the object placed in electrolysis?

Answer 33

Used as the negative electrode so metal atoms are deposited from the solution on to the object