UNIT 3 - Metals

Question 1

what binds the ions together in metals?

Answer 1

The electrostatic attraction of positive metal ions for the delocalised electrons

Question 2

what is electrolysis?

Answer 2

It is the decomposition of an ionic compound into its elements using electricity

Question 3

What is required if the products are to be identified in electrolysis?

Answer 3

A direct current (dc) supply

Question 4

what does each atom in a metal lose, and why?

Answer 4

its outer electrons, to form positive ions

Question 5

what do the ions form after the metal has lost its outer electrons to become an ion?

Answer 5

a regular three dimensional lattice of positively charged ions

Question 6

describe the outer electrons of a metal atom.

Answer 6

they are not attached to a particular atom and are free to move around, therefore they are delocalised

Question 7

what is an electrical current?

Answer 7

a flow of charged particles (e-, ions)

Question 8

why do metals conduct electricity?

Answer 8

because electrons can flow through them without chemical changes taking place

Question 9

what is the reactivity series in order?

Answer 9

1. pottasium
2. sodium
3. lithium
4. calcium
5. magnesium
6. aluminium
7. zinc
8. iron
9. tin
10. lead
11. copper
12. mercury
13. silver
14. gold

Question 10

what is the least reactive element?

Answer 10

gold (does not react at all)

Question 11

what do all metals above silver in the reactivity series combine with?

Answer 11

they combine with oxygen when heated to form a metal oxide

metal + oxygen –> metal oxide

Question 12

what happens the higher up the reactivity series the element is?

Answer 12

the higher the metal is in the reactivity series, the more violent the reaction

Question 13

what do all of the metals above aluminium react with in the reactivity series?

Answer 13

they react with water to form a metal hydroxide and hydrogen.

metal + water –> metal hydroxide + hydrogen

Question 14

what do all of the metals above copper in the reactivity series react with?

Answer 14

they react with a dilute acid to create salt and hydrogen.

metal + acid –> salt + hydrogen

Question 15

how can metals be placed in order of reactivity?

Answer 15

by comparing the rates at which they react

Question 16

what is an oxidation reaction?

Answer 16

one in which electrons are lost or oxygen is gained

Question 17

what is a reduction reaction?

Answer 17

one in which electrons are gained or oxygen is lost

Question 18

what is a Redox reaction?

Answer 18

a reaction which involves both reduction and oxidation reactions taking place at the same time

Question 19

what must be removed at the end of a redox reaction?

Answer 19

the electrons

Question 20

how do you balance redox equations?

Answer 20

by multiplying one or both of the ion-electron eqautions

Question 21

what does a displacement reaction involve?

Answer 21

it involves the formation of a metal from a solution containing its ions by reaction with a metal higher in the electrochemical series

Question 22

what non metal appears in the ECS?

Answer 22

hydrogen

Question 23

what does ECS stand for?

Answer 23

electrochemical series

Question 24

how can you place hydrogen in the ECS?

Answer 24

you can place it according to its reaction with dilute hydrochloric acid

Question 25

what is produced when metals displace hydrogen ions?

Answer 25

hydrogen gas

Question 26

where is hydrogen in the ECS?

Answer 26

between LEAD and COPPER

Question 27

what are ores?

Answer 27

they are naturally occurring compounds of metals, and most ores are oxides

Question 28

what were the first metals to be found and why?

Answer 28

gold, silver, and copper, because they are found uncombined in the earths crust, therefore their extractions do not require a chemical reaction - they are inert

Question 29

what dictates how strong a metals bonds are?

Answer 29

the reactivity of the metal, if the metal is very reactive then more energy is required to seperate or extract it

Question 30

what type of reaction is any metal from its ore?

Answer 30

a reduction reaction

Question 31

what can metals below copper in the reactivity series be extracted with?

Answer 31

heat alone

Question 32

what can be reduced to their metal by heating with carbon or carbon monoxide?

Answer 32

oxides of metals above mercury and below aluminium in the reactivity series

Question 33

what does a metal oxide + carbon create?

Answer 33

metal oxide + carbon --> metal + carbon dioxide

Question 34

what does a metal oxide + carbon monoxide create?

Answer 34

metal oxide + carbon monoxide --> metal + carbon dioxide

Question 35

why do metal oxide + carbon(monoxide) take place?

Answer 35

because the carbon bonds more strongly with the oxygen than the metal does

Question 36

why does heating with carbon not work for oxides of metals above zinc?

Answer 36

because the metal bonds more strongly with the oxygen than the carbon does

Question 37

how are all metals above zinc in the reactivity series obtained?

Answer 37

by the electrolysis of molten compounds using a direct current

Question 38

what happens when metal compounds are in the molten state?

Answer 38

the ionic lattice breaks and the ions are free to move around.

Question 39

how are metals formed from electrolysis?

Answer 39

the positive metal ions are attracted to the negative electrode, where they gain electrons and form metal atoms

Question 40

what do ions flow through?

Answer 40

solutions

Question 41

what do electrons flow through?

Answer 41

metal wires

Question 42

what do electrochemical cells convert chemical energy into?

Answer 42

electrical energy

Question 43

what do electrochemical cells contain?

Answer 43

they contain one substance which gives up electrons and another substance that takes in electrons

Question 44

what does a cell consist of?

Answer 44

-two different metals -an electrolyte to complete the circuit

Question 45

what is an electrolyte?

Answer 45

a substance which completes the circuit by allowing ions to flow through it

Question 46

how can metals be sorted?

Answer 46

they can be sorted accorded to their voltage in a league table - the ECS

Question 47

what is the ECS?

Answer 47

a list of metals (and hydrogen) in order of their ability to lose electrons and form ions in solution

Question 48

the higher a metal is in the ECS....

Answer 48

the more readily it loses electrons

Question 49

what will electrons flow from in a cell?

Answer 49

the metal higher in the ECS to the metal lower down through the wires and meter

Question 50

the further apart the metals are in the ECS...

Answer 50

the larger the voltage produced

Question 51

What does a half cell consist of?

Answer 51

A metal in contact with a solution of it’s ions

Question 52

When can electricity be produced?

Answer 52

Only when two half cells are joined together

Question 53

How do ions move between half cells?

Answer 53

Using an ion bridge (salt bridge) which completes the curcuit

Question 54

When can non-metals be used in half-cells?

Answer 54

If a graphite rod is used to make electrical contact with the solution

Question 55

What will the ion higher in the ECS do?

Answer 55

Give away electrons

Question 56

What will the ion lower in the ECS do?

Answer 56

Will gain the electrons given out by the ion higher in the ECS

Question 57

What does a redox reaction produce?

Answer 57

An electric current

Question 58

why must a direct current (dc) supply be used?

Answer 58

to make sure that only one product is being produced at each electrode