3.5 - Metals

Question 1

how metal can be extracted from its ore

Answer 1

using a blast furnace
reacting with more reactive material
electrolysis

Question 2

reactivity series positions

Answer 2

• tendency to become oxidised is linked to how reactive a metal is
• metals higher up are less resistant to oxidation than
• metals placed lower down which are more resistant to oxidation, reacts with water
• position of the metal on the reactivity series determines the method of extraction

Question 3

Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium

PSL CMA

Answer 3

• extracted by ELECTROLYSIS of the molten chloride or oxide
• large amounts of ELECTRICITY are required, which makes this an EXPENSIVE process

Question 4

Zinc
Iron
Copper

ZIC

Answer 4

• extracted by heating with a reducing agent such as carbon or carbon monoxide in a BLAST FURNACE
• cheap process as carbon is CHEAP and can also be a source of heat

Question 5

Silver
Gold

Answer 5

• found as PURE elements

Question 6

reactivity series from most to least reactive

Answer 6

Potassium
Sodium
Lithium
Calcium
Magnesium
Aluminium
Zinc
Iron
Copper
Silver
Gold

Question 7

uses of aluminium and its properties

Answer 7

aircraft bodies - high strength-to-weight ratio (low density)

saucepans - very good conductor of heat and unreactive

overhead electrical cables - very good conductor of electricity

food cans - non-toxic, resistant to corrosion and resistant to acidic food stuffs

Question 8

uses of copper

Answer 8

electrical wiring - very good conductor of electricity and ductile

saucepans - very good conductor of heat, unreactive, malleable

water pipes - unreactive (does not react with water), non-toxic and malleable

Question 9

uses of iron

Answer 9

building material - good strength, malleable and ductile, relatively inexpensive

catalyst - increases the rate of reaction without being used up

Question 10

steels alloys its uses: mild

Answer 10

alloyed with - 0.25% carbon

• car body panels and wiring
• soft and malleable

Question 11

steels alloys and its uses: high carbon

Answer 11

alloyed with - 0.5-1.4% carbon

• tools, e.g. chisels
• hard

Question 12

steels alloys and its uses: stainless steel

Answer 12

alloyed with - 20% chromium and 10% nickel

• cutlery, sinks and chemical plants
• strong and resistant to corrosion

Question 13

alloy and example

Answer 13

a mixture of two or more metals or metal with a non-metal such as carbon
e.g. steel is made from iron and carbon

Question 14

alloy properties

Answer 14

• stronger and harder
• resistant to corrosion or extreme temperatures
• makes it more useful than pure metals

Question 15

why is an alloy harder than a pure metal

Answer 15

• pure metal has layers so the atoms can slide over more easily
• alloy has different sized atoms which are randomly arranged which prevents layers sliding over

Question 16

brass is a common example of an alloy which contains

Answer 16

70% copper and 30% zinc

Question 17

metallic lattice by a 2-D diagram

Answer 17

• outer electrons become ‘delocalised’ which means they are free to move throughout the whole structure
• metals have a giant regular arrangement of layers of positive ions surrounded by a sea of delocalised electrons

Question 18

metal + acid ⟶

Answer 18

salt + hydrogen
__(s) + H2SO4 (aq) → __SO4 (aq) + H2 (g)

Question 19

rusting equation

Answer 19

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

Question 20

what must be present for rusting to occur

Answer 20

Oxygen and water

Question 21

oxidation is any reaction which

Answer 21

a substance gains oxygen
- lose electrons

Question 22

reduction is any reaction which

Answer 22

a substance loses oxygen
- gain electrons

Question 23

oxidising agent

Answer 23

what supplies the oxygen

Question 24

reducing agent

Answer 24

removes the oxygen

Question 25

investigate the reactions between dilute hydrochloric and sulfuric acids with the metals magnesium, iron and zinc

Answer 25

• add 5 cm3 of dilute hydrochloric acid to each of three test tubes
• add 1 cm length of magnesium ribbon to the first tube, observe and note down what you see
• use a lighted splint to test for any gases given off
• to the second test tube add a few pieces of iron filings and to the third some zinc turnings
• observe what happens, test for any gases and note down your observations
• repeat the experiment with dilute sulfuric acid

Question 26

magnesium reacting with dilute hydrochloric acid dilute sulfuric acid

Answer 26

hydrochloric acid - dissolves quickly, gets hot, gas given off which goes pop with a lighted splint, colourless solution left

sulfuric acid - bubbling, splint goes pop, metal dissolves

Question 27

magnesium reacting with dilute hydrochloric acid dilute sulfuric acid

Answer 27

hydrochloric acid - very slow bubbling sulfuric acid - slow reaction, small bubbles seen

Question 28

magnesium reacting with dilute hydrochloric acid dilute sulfuric acid

Answer 28

hydrochloric acid - bubbles given off, metal slowly dissolves
sulfuric acid - metal dissolves forming colourless solution, gas given off slowly

Question 29

metal​ ​+​ ​oxygen​ ​→​ ​

Answer 29

metal​ ​oxide

Question 30

rusting​ ​can​ ​be​ ​prevented​ ​by​ ​excluding​ ​oxygen​ ​and​ ​water​ ​e.g.​ by:

Answer 30

o painting
o coating​ ​with​ ​plastic
o using​ ​oil​ ​or​ ​grease

Question 31

reaction between different metals and acids (hydrochloric acid and sulphuric acid)

Answer 31

you​ ​can​ ​observe​ ​the​ ​reaction​ ​of​ ​different​ ​metals​ ​with​ ​acids,​ ​as​ ​the​ ​most​ ​reactive
will​ ​give​ ​off​ ​large​ ​amounts​ ​of​ ​H​2​​ ​gas​ ​bubbles​ ​and​ ​the​ ​least​ ​reactive​ ​will​ ​not​ ​give off​ ​any​ ​at​ ​all

● metal​ ​+​ ​acid​ ​→​ ​hydrogen​ ​+​ ​salt