Topic 5 Using Spec

Question 1

What are electrolytes

Answer 1

Ionic compounds that dissolve in water to make a solution that conducts electricity

Question 2

What happens when ionic compounds are melted or dissolved in water

Answer 2

The ions are free to move around and the liquids will conduct electricity

Question 3

What are positively charged ions attracted to

Answer 3

Negative electrode ( cathode)

Question 4

What are negatively charged ions attracted to

Answer 4

Positive electrode (anode)

Question 5

When do ions attract to the electrode

Answer 5

When a voltage is applied an electrolyte

Question 6

What happens when an ion touches an electrode

Answer 6

Electrons can be transferred producing elements

Question 7

What is electrolysis used for

Answer 7

Extracting reactive metals from molten ores

Question 8

What is the anode usually made of and why

Answer 8

Carbon because it is a good conductor and is cheap

Question 9

What happens at the cathode

Answer 9

Aluminium is formed

Question 10

What are disadvantages of electrolysis

Answer 10

Lots of energy needed to produce the electric current

Costs money

Question 11

Describe copper chloride solution in electrolysis

Answer 11

Applying electricity across copper chloride solution with graphite electrodes produces copper at the cathode and chloride gas at the anode

Question 12

Describe molten lead bromide in electrolysis

Answer 12

When we use graphite electrodes to apply electricity across molten lead bromide, we form lead (metal) at the cathode and bromine (non-metal) at the anode.
Lead is present if a shiny metal forms around the cathode
Bromine is observed as a brown gas

Question 13

Describe sodium chloride in electrolysis

Answer 13

Chloride produces hydrogen gas at cathode and chlorine gas at anode
Electrodes are graphite or platinum
Hydrogen can be detected using lit splint and squeaky pop sound
Chlorine gas detected by smell

Question 14

Describe sodium sulfate in electrolysis

Answer 14

Graphite electrodes
Hydrogen and cathode and oxygen at anode
Hydrogen detected by split and squeaky pop
Oxygen detected by glowing splint

Question 15

What is produced when halide ions are present at the anode

Answer 15

Respective halogen

Question 16

What happens if there are no halide ions in the anode

Answer 16

Oxygen forms

Question 17

What is produced in the cathode when a metal is higher than oxygen in the reactivity series

Answer 17

Hydrogen

Question 18

What is produced in the cathode when metal is lower than hydrogen in the reactivity series

Answer 18

The metal is produced

Question 19

In the cathode what half question takes place

Answer 19

Pb2(+) - 2e(-) -> Pb

Question 20

What half equations takes place at the anode

Answer 20

2Br(-) -> Br2 + 2e(-)

Question 21

How can you purify copper using copper sulfate in electrolysis

Answer 21

Copper ions will go into the electrolyte solid copper sulfate
The Cu2+ ions will be attracted to the cathode and pure copper will form

Question 22

What metals are found in the earths crust

Answer 22

Gold and platinum (highly unreactive metals )

Question 23

What is oxidation

Answer 23

Gain of oxygen and loss of electrons

Question 24

What is reduction

Answer 24

Loss of oxygen and gain of electrons

Question 25

What is a displacement reaction

Answer 25

Where a more reactive metal that forms positive ions more easily can remove a less reactive metal from a compound

Question 26

Describe displacement in terms of oxidation and reduction

Answer 26

More reactive metal loses electrons (oxidation) and the less reactive metal gains electrons (reduction)

Question 27

What are the 4 stages of life cycle assessment

Answer 27

Collecting the raw materials needed Making and packaging the product Product use Disposal of the product

Question 28

What are benefits of recycling metals

Answer 28

Less burning of fossil fuels Less energy used Conserves finite resources Fewer waste rock heaps

Question 29

What does oxidation of metals result In

Answer 29

Corrosion

Question 30

How can the rusting of iron be prevented

Answer 30

Exclusion of oxygen Exclusion of water Sarcrifical protection

Question 31

What are the three methods to stops metals from corroding

Answer 31

Coatings - apply a coating witch acts like a barrier such as greasing, painting or electroplating Sarcrifical method - metal that that requires protection will have a more reactive metal attached to it Galvanising - metal that needs protecting is sprayed With a more reactive metal

Question 32

Disadvantages of coating

Answer 32

If the coating gets damaged, the metal becomes exposed so corrosion can take place

Question 33

How can electroplating be used to improve the appearance of a metal

Answer 33

coat a cheaper metal with a more expensive one. This gives the cheaper metal the appearance of the more expensive metal, which could be gold or silver. This gives us the option of buying cheaper jewellery.

Question 34

How is electroplating used in electrolysis

Answer 34

placing the metal to be electroplated at the negative electrode (cathode) and the coating metal at the positive electrode (anode).