Electrolysis, Dynamic Equilibrium and Electroplating (paper1)

Question 1

Name a use for gold and why

Answer 1

Spacesuit visors for radiation protection

Question 2

Name a use for copper and why

Answer 2

Building construction and wiring because it can conduct electricity

Question 3

Name a use for aluminium and why

Answer 3

Overhead electrical cables because it resists corrosion, does not conduct electricity

Question 4

What is brass

Answer 4

An alloy of copper and zinc

Question 5

What happens to ions of a substance when dissolved in water

Answer 5

They are free to move

Question 6

Define electrolysis

Answer 6

A process where electricity is used to make a chemical change happen that wouldn’t happen otherwise

Question 7

Name all diatomic elements

Answer 7

Br, I, N, Cl, H, O, F, At

Question 8

What does not spontaneous mean

Answer 8

Doesn’t happen on its own

Question 9

What forces electrolysis to happen

Answer 9

electrical energy from a battery

Question 10

What happens at the anode

Answer 10

Oxidation, and it pulls the electrons

Question 11

What happens at the cathode

Answer 11

Reduction, and it pushes electrons

Question 12

What happens to elements that don’t have a charge

Answer 12

They pair up

Question 13

At the anode, what is the layout of the half equation

Answer 13

X->X+Y

Question 14

At the cathode, what is the half equation layout

Answer 14

X + Y->X

Question 15

What are the ions called that go to the anode

Answer 15

Anions

Question 16

What are the ions called that go to the cathode

Answer 16

Cations

Question 17

How many ions are present when electrolysing molten substances

Answer 17

2

Question 18

What is the most common type of reversible reaction

Answer 18

Biochemical, they take place in living organisms

Question 19

What is an important industrial reaction

Answer 19

The Haber process

Question 20

What are the names for the ways the reaction moves

Answer 20

Endothermic and exothermic

Question 21

When is the reaction exothermic

Answer 21

When it’s giving out heat

Question 22

When is a reaction endothermic

Answer 22

When it gets colder or absorbs heat

Question 23

What happens at a certain point in a reversible reaction

Answer 23

Both forward and backward reactions are happening at the same speed so the amount of products and reactants aren’t changing

Question 24

Where does a dynamic equilibrium only occur

Answer 24

A closed system

Question 25

What would happen if it was in an open system

Answer 25

Gases would escape and so equilibrium would not be achieved

Question 26

What's the haber process equation

Answer 26

Nitrogen+hydrogen<=> ammonia

Question 27

What are the three factors we can change to influence the position of an equilibrium

Answer 27

Temp, concentration, pressure

Question 28

Do an equilibrium have to be in the middle

Answer 28

No

Question 29

What happens if the reaction increases in temp

Answer 29

It moves in the endothermic direction

Question 30

What happens if the reaction decreases temp

Answer 30

It moves in the exothermic direction

Question 31

What happens if we increase the gas pressure in a reaction

Answer 31

It moves in the direction that forms fewer gas molecules

Question 32

What happens if we decrease the gas pressure

Answer 32

It moves in the direction that forms more gas molecules

Question 33

What happens if we increase the concentration in a reaction

Answer 33

It moves in the direction that uses up the substance that has been added

Question 34

What happens if we decrease the concentration in a reaction

Answer 34

It moves in the direction that forms more the substance that has been removed

Question 35

What happens if you add a catalyst to the reaction

Answer 35

It stays the same

Question 36

Where does the hater process get its nitrogen

Answer 36

The air

Question 37

Where does the haber process get its hydrogen from

Answer 37

Natural gas

Question 38

What conditions does the haber process have to have to work

Answer 38

High temps- Temp of 450^ High pressure- 20x normal atmospheric The presence of an iron catalyst

Question 39

What comprise is made in the haber process

Answer 39

A higher temp = a quicker rate of reaction but it produces less ammonia so 450 is a compromise

Question 40

What does higher pressure in the haber process produce

Answer 40

More ammonia

Question 41

What does the high pressure in the haber process run the risk of

Answer 41

Explosions

Question 42

What is electroplating used for

Answer 42

Preventing corrosion or to make something pretty

Question 43

What is electroplating

Answer 43

Coating the surface of one metal with a thin layer of another metal

Question 44

What are the best electrical conductors

Answer 44

Silver and copper

Question 45

What are the downsides of electroplating with silver and copper

Answer 45

They tarnish in air

Question 46

Explain the advantages and disadvantages of gold electroplating

Answer 46

It's a good conductor and doesn't tarnish but it's expensive

Question 47

What is the object that is to be electroplated

Answer 47

The cathode

Question 48

What can iron and steel be covered in to prevent rusting

Answer 48

Zinc

Question 49

What is the process in which zinc covers iron

Answer 49

Galvanising

Question 50

What is zinc acting as

Answer 50

A sacrificial metal that stops water reaching the iron or steel

Question 51

Does sacrificial protection still happen if the layer of zinc is damaged?

Answer 51

Yes

Question 52

What is an alloy

Answer 52

A mixture of a metal element with one or more other elements

Question 53

How is an alloy steel made

Answer 53

By adding other elements to iron

Question 54

How do you create different properties in alloy steels

Answer 54

Change their composition

Question 55

What steel resists rusting

Answer 55

Stainless steel

Question 56

What does stainless steel contain

Answer 56

Chromium, which reacts with oxygen to form chromium oxide

Question 57

What are the ions called in a displacement reaction that don't change

Answer 57

Spectator ions

Question 58

What's a redox reaction

Answer 58

A reaction where one substance is oxidised and one substance is reduced

Question 59

What is the ionic equation for every BAWS reaction

Answer 59

OH- + H+ -> H2O