C10.1 - 10.2 - Properties of metals and Reactivity series

Question 1

Properties of metals

Answer 1

High MP and BP
Good conductors of heat
Good conductors of electricity
Shiny
Sonorous (ring when struck)
Ductile (can be drawn into wires)
Malleable (can be hammered into shape)

Question 2

Structure of a metal

Answer 2

Metal atoms give up their electrons to form positive cations.

The electrons given up create a sea of delocalized electrons which are attracted to the positive ions holding the structure.

This creates a strong lattice like structure for the metal

Question 3

Explain why metals are malleable, ductile and good conductors of electricity relating to metallic bonding.

Answer 3

Good conductors of electricity:
Sea of delocalized electrons in which electrons can carry current throughout a metal

Ductile and malleable:
Because metallic bonds are not as rigid as bonds in diamond. Ions can move around in different positions.

Question 4

What is an alloy

Answer 4

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

Question 5

Why are alloys stronger than pure metals

Answer 5

The structure of an alloy is irregular as it contains different sized atoms from being a mixture. Due to different size atoms it’s harder to break the metal.

Regular metals with repeating lattice patterns can be weak as the slightest difference between the planes of the atoms will break at that point.

Question 6

Brass is an alloy of

Answer 6

copper and zinc

Adding zinc makes the material more malleable

Question 7

Bronze is an alloy of

Answer 7

copper and tin

Adding tin increases the hardness of the material

Question 8

Steel is an alloy of

Answer 8

iron that contains carbon

Question 9

What are the different types of steel and their features

Answer 9

High carbon steel:
Strong but brittle
Used to make cutting tools and blades

Low carbon steel:
Soft but malleable
Used in making car bodies

Stainless steel (Steel containing chromium and nickel):
Strong and resistant to corrosion
Used in cooking utensils and cutlery

Question 10

More reactive metals

Answer 10

react with oxygen to form oxides

i.e 2Ca + O2 ==> 2CaO

Question 11

Less reactive metals such as gold do not react with

Answer 11

oxygen

Question 12

The more reactive a metal is the easier it is to

Answer 12

form compounds and the harder it is to break those compounds down

Question 13

The most reactive metals i.e Potassium, sodium, lithium and calcium

Answer 13

react with water at room temperature

2Na + 2H2O ==> 2NaOh + H2

Question 14

Less reactive metals such as magnesium and iron react with

Answer 14

steam

Mg + H2O ==> MgO + H2

Question 15

Some of the mid reactivity series metals produce hydrogen when react with

Answer 15

dilute acids
Magnesium, aluminum, zinc and iron all release hydrogen when react with dilute HCI
Zn + 2HCI ==> ZnCl2 + H2

Question 16

Metals below hydrogen in the reactivity series do not

Answer 16

form hydrogen with water or dilute acids

Question 17

Displacement reactions are examples of

Answer 17

redox reactions

more reactive metal loses electrons (oxidize) and less reactive metal gains electrons (reduces)

Question 18

What happens in the reaction magnesium + copper oxide

Answer 18

==> magnesium oxide + copper

magnesium has been oxidized and gained oxygen while copper has been reduced and lost oxygen

Question 19

In a redox reaction the

Answer 19

reducing agent is always oxidized

oxidizing agent is always reduced

Question 20

What happens in the displacement reaction of

zinc + copper(II) sulfate solution

Answer 20

==> zinc sulfate solution + copper
Zinc displaces copper as it is more reactivity
Zinc is oxidized and copper is reduced

Question 21

Why are metals dense

Answer 21

because atoms are packed as close as possible

Question 22

Why is a metal maellable

Answer 22

because their regular layers make it easy to slide over each other when a force is applied