Electrolysis

Question 1

What is an electrolyte?

Answer 1

A substance that undergoes electrolysis and must contain ions.

Question 2

Can covalent compounds be electrolytes?

Answer 2

No, covalent compounds do not contain ions and cannot be electrolytes.

Question 3

What is the role of electrodes in electrolysis?

Answer 3

Electrodes pass electricity into and out of the electrolyte.

Question 4

Why is carbon often used as an electrode?

Answer 4

Because it conducts electricity and is fairly chemically inert.

Question 5

What is another material that can be used as an electrode?

Answer 5

Platinum can also be used as it is chemically inert.

Question 6

What are the characteristics of platinum as an electrode?

Answer 6

It is rarer and more expensive than carbon.

Question 7

What is the positive electrode called?

Answer 7

Anode.

Question 8

What is the negative electrode called?

Answer 8

Cathode.

Question 10

What is electrolysis?

Answer 10

A chemical process that uses electricity to drive a non-spontaneous reaction.

Question 11

What is the positive electrode called in electrolysis?

Answer 11

Anode

Question 12

What happens to negative ions at the anode?

Answer 12

They move here and lose electrons, becoming oxidised.

Question 13

What is the negative electrode called in electrolysis?

Answer 13

Cathode

Question 14

What happens to positive ions at the cathode?

Answer 14

They move here and gain electrons, becoming reduced.

Question 15

What is an electrolyte?

Answer 15

A substance that conducts electricity through the movement of ions.

Question 16

What are electrodes made of in electrolysis?

Answer 16

An unreactive (inert) substance, most commonly graphite.

Question 17

Why are electrodes made of inert substances?

Answer 17

To ensure they do not react with the electrolyte.

Question 18

What is electrolysis?

Answer 18

A chemical process that uses electricity to drive a non-spontaneous reaction.

Question 19

What is the positive electrode called in electrolysis?

Answer 19

Anode

Question 20

What happens to negative ions at the anode?

Answer 20

They move here and lose electrons, becoming oxidised.

Question 21

What is the negative electrode called in electrolysis?

Answer 21

Cathode

Question 22

What happens to positive ions at the cathode?

Answer 22

They move here and gain electrons, becoming reduced.

Question 23

What is an electrolyte?

Answer 23

A substance that conducts electricity through the movement of ions.

Question 24

What are electrodes made of in electrolysis?

Answer 24

An unreactive (inert) substance, most commonly graphite.

Question 25

Why are electrodes made of inert substances?

Answer 25

To ensure they do not react with the electrolyte.

Question 27

What happens during electrolysis?

Answer 27

Ions move towards the electrodes.

Question 28

What determines the direction of ion movement during electrolysis?

Answer 28

The direction they move in depends on their charge.

Question 29

What occurs when ions reach the electrode?

Answer 29

They lose or gain electrons to become atoms.

Question 30

What happens to negatively charged ions during electrolysis?

Answer 30

They lose electrons to become neutral atoms - they are oxidised.

Question 31

What happens to positively charged ions during electrolysis?

Answer 31

They gain electrons to become neutral atoms - they are reduced.

Question 32

What are negative ions also known as?

Answer 32

Negative ions are also known as anions.

Question 33

What happens to negative ions in terms of electrons?

Answer 33

Negative ions lose electrons.

Question 34

What occurs to the ions during this process?

Answer 34

The ions are oxidised.

Question 35

Which ion is attracted to the positive electrode?

Answer 35

The Cl- ion is attracted to the positive electrode.

Question 36

How many electrons does the Cl- ion lose?

Answer 36

The Cl- ion loses one electron.

Question 37

What charge does the Cl- ion have after losing an electron?

Answer 37

It has a 1- charge.

Question 38

What does it mean for the Cl- ion after it has lost an electron?

Answer 38

It has been oxidised.

Question 39

What is the charge of the Cl- ion after oxidation?

Answer 39

Now it has a neutral charge.

Question 41

What are negative ions also known as?

Answer 41

Negative ions are also known as anions.

Question 42

What happens to negative ions in terms of electrons?

Answer 42

Negative ions lose electrons.

Question 43

What occurs to the ions during this process?

Answer 43

The ions are oxidised.

Question 44

Which ion is attracted to the positive electrode?

Answer 44

The Cl- ion is attracted to the positive electrode.

Question 45

How many electrons does the Cl- ion lose?

Answer 45

The Cl- ion loses one electron.

Question 46

What charge does the Cl- ion have after losing an electron?

Answer 46

It has a 1- charge.

Question 47

What does it mean for the Cl- ion after it has lost an electron?

Answer 47

It has been oxidised.

Question 48

What is the charge of the Cl- ion after oxidation?

Answer 48

Now it has a neutral charge.

Question 49

What are positive ions called?

Answer 49

Positive ions are called cations.

Question 50

What happens to cations during the process?

Answer 50

Cations gain electrons.

Question 51

What is the result of gaining electrons?

Answer 51

The ions are reduced.

Question 52

What attracts cations?

Answer 52

Cations are attracted to the negative electrode.

Question 53

What charge does a cation have after gaining one electron?

Answer 53

After gaining one electron, it has a 1+ charge.

Question 54

What does it mean for a cation to be reduced?

Answer 54

It has been reduced and now has a neutral charge.

Question 55

What is a characteristic of ionic substances?

Answer 55

Ionic substances have very high melting points.

Question 56

What is a challenge with ionic substances due to their melting points?

Answer 56

It sometimes requires too much energy to have them as molten.

Question 57

How can we make ionic substances conductive?

Answer 57

We can dissolve them in water, allowing ions to move around and carry a charge.

Question 58

What must we consider when ionic substances are dissolved in water?

Answer 58

We need to consider the ions in water, specifically H+ and OH-.

Question 59

What is a potential issue when dissolving ionic substances in water?

Answer 59

The products aren't always what we expect.