Metals and Corrosion

Question 1

What does malleable mean?

Answer 1

That the metal can be hammered or rolled into thin sheets.

Question 2

Which metal is the most malleable?

Answer 2

Gold ( Au )

Question 3

How/Where is the malleability of a metal is beneficial and desirable?

Answer 3

-making pots and pans
-sheets of metal for construction
-jewelry

Question 4

Where are metals used because of their strength?

Answer 4

-Building/Construction
-Car production

Question 5

What are the 5 strongest metals?

Answer 5

Iron, Titanium, Tungsten, Chromium, Vanadium

Question 6

What is density measured in?

Answer 6

g/cm3

Question 7

Why can some metals float on water?

Answer 7

Their density is less than that of water so they will float.

Question 8

Why are metals like aluminium and magnesium desirable in the construction industry?

Answer 8

-light
-strong
-durable
Magnesium is a good insulator.

Question 9

What metals are desirable in the construction industry?

Answer 9

-aluminium
-magnesium

Question 10

Where are metals used because of their electrical conductivity?

Answer 10

-Wires
-Batteries
-Hearing Aids

Question 11

Which 3 metals are the best conductors of electricity?

Answer 11

-silver
-copper
-gold

Question 12

Why do pans and radiators relate to a metals ability to conduct heat?

Answer 12

-They conduct heat well
-Chemically Unreactive
-Metals are good conductors of heat = perfectly suited for cooking implements and radiators

Question 13

Which 3 metals are the best conductors of heat?

Answer 13

-Copper
-Aluminium
-Silver

Question 14

What is a ‘alloy’?

Answer 14

Metals are often mixed to form alloys.
An alloy is made to improve the properties of the metal.

Question 15

What is the most well-known alloy?

Answer 15

STEEL

Question 16

Is steel a metal?

Answer 16

No, it is a mixture

Question 17

How is steel formed?

Answer 17

When iron is mixed with a small amount of carbon. STEEL is tougher than iron.
Main element = iron
Added element = carbon

Question 18

What are the properties and uses of STEEL?

Answer 18

-construction , engineering
-agriculture, manufacture of cars
-STRONG + DURABLE

Question 19

What is stainless steel made of?

Answer 19

Main element = iron
Added element = chromium, carbon

Question 20

What are the properties and uses of stainless steel?

Answer 20

-High tensile strength
-Temperature resistance
- Very durable
-Doesn’t rust
- Unreactive
-Good conductor of heat
-cutlery, pots and pans, jewelry

Question 21

What is brass made of?

Answer 21

Main element = copper
Added element = zinc

Question 22

What are the properties and uses of brass?

Answer 22

-Low friction
-Good conductor
-Low melting point
-Malieable
-Ductile
-Anti-microbial
-instruments, handles, candle sticks, cutlery, plumbing parts

Question 23

What is duralumin made of?

Answer 23

Main element = aluminium
Added element = copper, magnesium, maganese

Question 24

What are the properties and uses of duralumin?

Answer 24

-Strong, light-weight, durable, reflective, maileable
-aircrafts, make rods, wires, firearms

Question 25

What is amalgam made of?

Answer 25

Main elements = Mercury Added elements = Silver, Tin, Copper

Question 26

What are the properties and uses of amalgam?

Answer 26

-Durable, strong -Fillings in teeth

Question 27

What are the karat ratings?

Answer 27

6 = 1/4 = 25% 12 = 1/2 = 50% 18 = 3/4 = 75% 24 = ~1 = 99.9%

Question 28

Why is it necessary to alloy gold with other metals?

Answer 28

To increase the durability and hardness. It would be too soft otherwise.

Question 29

What are some metals which are added to gold to make an alloy?

Answer 29

Copper, silver, palladium, nickel, zinc

Question 30

If an 18 carat gold ring weighed 6.2g. What is the mass of actual Gold in the ring?

Answer 30

18 karat - 75% gold 6.2 / 100 = 0.062 0.062 x 75 - 4.65g

Question 31

Why do some metals react with water?

Answer 31

They brave a low melting point and the heat generated from the reaction is enough to melt the metal.

Question 32

Evidence of a chemical reaction?

Answer 32

-bubbles -temperature change (exothermic reaction) -colour change

Question 33

Out of magnesium, zinc and copper, order them in order of reactivity in ACID.

Answer 33

-magnesium -zinc -copper

Question 34

What element does potassium permanganate contain a lot of?

Answer 34

OXYGEN

Question 35

What happens when potassium permanganate is heated?

Answer 35

It breaks down releasing oxygen which passes over the hot metal forming a metal oxide.

Question 36

What is the word equation for the reaction of iron?

Answer 36

iron + oxygen --> iron oxide

Question 37

Place magnesium, zinc and iron in order of reactivity when heated with ceramic wool.

Answer 37

-Magnesium -Zinc -Iron

Question 38

What is the name of the metal compound in the ore magnetite?

Answer 38

IRON OXIDE

Question 39

What is the name of the metal compound in the ore haematite?

Answer 39

FERRIC OXIDE

Question 40

What is the name of the metal compound in the ore bauxite?

Answer 40

ALUMINIUM OXIDE

Question 41

What is the name of the metal compound in the ore galena?

Answer 41

LEAD SULFIDE

Question 42

What is the name of the metal compound in the ore malachite?

Answer 42

COPPER CARBONATE HYDROXIDE

Question 43

What is meant by electrolysis?

Answer 43

The splitting of a compound using electricity

Question 44

What is the link between a metals reactivity and its date of discovery?

Answer 44

Less reactive metals being discovered earlier than more reactive ones.

Question 45

What was the discovery in 1800 and how did it lead to the discovery of many new metals?

Answer 45

Batteries Invented by Alessandro Vaita Discovery of electric = allowing electrolysis

Question 46

When does rust form?

Answer 46

When iron reacts with oxygen to form iron oxide.

Question 47

How can metals be protected by corrosion?

Answer 47

Putting a physical barrier between the metal and the water/oxygen. Painting, coating it with another material, covering in grease KNOWN AS PHYSICAL PROTECTION

Question 48

What are the two methods of protecting against rust?

Answer 48

PHYSICAL PROTECTION SACRIFICIAL PROTECTION

Question 49

What is galvanising?

Answer 49

Coat iron or steel with a protective layer of zinc. Zinc is higher in the reactivity series and so will corrode to protect the iron.

Question 50

What is an alloy? Give an example.

Answer 50

brass bronze steel duralumin amalgam

Question 51

How are alloys produced?

Answer 51

-melting components -mixing and cooling them -result = hardened material (alloy)