Metals and the Reactivity Series

Question 1

Compare the general physical properties of metals and non-metals.

Answer 1

• metals have high melting/boiling points, non-metals have low
• metals are good electric conductors, non-metals are electric insulators
• metals are good thermal conductors, non-metals are thermal insulators
• metals are ductile/malleable, not non-metals

Question 2

State the order of the reactivity series.

Answer 2

potassium
sodium
calcium
magnesium
aluminium
carbon
zinc
iron
hydrogen
copper
silver
gold

Question 3

Where is hydrogen in the reactivity series?

Answer 3

below iron, above copper

Question 4

Where is carbon in the reactivity series?

Answer 4

below aluminium, above zinc

Question 5

Reaction of metals with water.

Answer 5

metal + water → metal hydroxide + hydrogen

Question 6

Group I elements are ____ reactive than Group II.

Answer 6

more

Question 7

Which elements are more reactive, group 1 or 2?

Answer 7

group 1

Question 8

For metals, what does the group define about their reactivity?

Answer 8

the lower the group the more reactive

Question 9

For metals, what does the mass of an element define about their reactivity?

Answer 9

heavier elements further down the group are more reactive

Question 10

Mnemonic for reactivity series.

Answer 10

Please send cats, monkeys and zebras charging into hot countries,
Signed Greg

Question 11

Reaction of metals with dilute acids.

Answer 11

metal + acid → salt + hydrogen

Question 12

Reaction of metals with oxygen.

Answer 12

metal + oxygen → metal oxide

Question 13

What is aluminium used for and why?

Answer 13

• manufacture of aircraft: low density
• manufacture of overhead electrical cables: low density + good electrical conductivity
• food containers: resistance to corrosion

Question 14

What is copper used for and why?

Answer 14

electrical wiring: good electrical conductivity and ductility

Question 15

Describe the reaction of potassium with cold water.

Answer 15

• vigorous effervescence
• hydrogen gas released
• metal floats on water surface, gets smaller as it reacts
• after a short while the gas given off will ignite and a lilac-coloured flame seen

Question 16

Describe the reaction of sodium with cold water.

Answer 16

• similar to potassium, but reaction is less vigorous so the hydrogen gas may not ignite

Question 17

Describe the reaction of calcium with cold water.

Answer 17

• solid metal sinks
• bubbles produced on surface of the metal (much slower than K and Na)
• as metal disappears, solution becomes cloudy as calcium hydroxide is insoluble

Question 18

Describe the reaction of magnesium with cold water/steam.

Answer 18

no reaction with cold water, but reacts with steam to form hydrogen and white powder (magnesium hydroxide)

Question 19

The solid metal sinks and bubbles produced on surface of the metal. What reaction is this?

Answer 19

calcium and water

Question 20

Describe the reaction of magnesium with dilute HCl.

Answer 20

strong: bubbles form quickly on the surface, metal slowly disappears

Question 21

Describe the reaction of zinc with dilute HCl.

Answer 21

bubbles slowly form

Question 22

Describe the reaction of iron with dilute HCl.

Answer 22

very slow, must be powdered iron

Question 23

Describe the reaction of copper/silver/gold with dilute HCl.

Answer 23

none

Question 24

A metal reacts with dilute HCl. The reaction is slow and the metal must be powdered. What is the metal?

Answer 24

iron

Question 25

A metal reacts with dilute HCl. The reaction is bubbles forming slowly. What is the metal?

Answer 25

zinc

Question 26

Explain the apparent unreactivity of aluminium.

Answer 26

aluminium oxide forms quickly when aluminium is exposed to air, creating an oxide layer that creates a perfect barrier around the aluminium, preventing further metal reaction

Question 27

How can displacement reactions be used to extract metals?

Answer 27

• carbon is more reactive than the metal, so it displaces the metal from its oxides
• produces pure metal and carbon dioxide

Question 28

How can we extract metals less reactive than carbon?

Answer 28

mixing them with carbon (most likely as charcoal) and heating them to high temperatures

Question 29

A _____ reactive metal displaces a _____ reactive metal.

Answer 29

more/less

Question 30

What is a displacement reaction?

Answer 30

a more reactive element is taking the place of a less reactive element

Question 31

State the conditions required for the rusting of iron and steel.

Answer 31

oxygen and water in the air

Question 32

What is the chemical name for rust?

Answer 32

hydrated iron(III) oxide

Question 33

Word equation for rusting

Answer 33

iron + water + oxygen → hydrated iron(III) oxide

Question 34

Symbol equation for rusting

Answer 34

2Fe(s) + 2H2O(l) + O2(g) → Fe2O3·H2O(s)

Question 35

State some common barrier methods.

Answer 35

• painting
• greasing
• coating with plastic

Question 36

Which metal quickly forms an oxide layer, appearing unreactive?

Answer 36

aluminium

Question 37

Describe how barrier methods prevent rusting.

Answer 37

by excluding oxygen or water

Question 38

What is a barrier method?

Answer 38

set of techniques to prevent corrosion by preventing oxygen and water coming into contact with the metal surface

Question 39

What is zinc in galvanising an example of?

Answer 39

barrier method and sacrificial protection

Question 40

Describe the use of zinc in galvanising.

Answer 40

iron/steel objects are completely coated in a thin layer of zinc, the zinc forms a barrier between the iron and oxygen in the atmosphere

Question 41

What is sacrificial protection?

Answer 41

protecting a metal from corrosion by allowing another more reactive metal, to corrode instead

Question 42

What is sacrificial protection often used for?

Answer 42

hulls of ships, as salt water accelerates rusting

Question 43

Describe sacrificial protection.

Answer 43

• iron/steel placed in contact with a more reactive metal
• more reactive metals loses electrons more easily than iron
• presence of electrons prevents iron from oxidising
• while more reactive metals than iron remain in contact with the iron, it remains protected