Reactivity Series

Question 1

which 4 Reactivity Series metals react w/ water? + eqn

Answer 1

Potassium, Sodium, Calcium, Magnesium
metal + H2o -> metal hydroxide + H2

i.e. 2K(s) + 2H2o(l) -> 2KOH(aq) + H2(g)

https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 14

Question 2

which reactivity series metals react w/ steam + eqn

Answer 2

Magnesium, Aluminium, Zinc… Iron
metal + steam -> metal oxide + H2

Potassium, Sodium, Calcium
can react, 2 dangerous

i.e. Zn(s) + H2o(g) -> ZnO(s) + H2(g)

https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 14

Question 3

define displacement in metals

Answer 3

more reactive metal
displaces less reactive metal from
salt soln

Question 4

displacement experiement setup

Answer 4

https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 13

Question 5

why aluminium removed from reactivity series?

Answer 5

has protective layer (Al2O3)
- Al react readily w/ Oxygen -> Al2o3
- Al2O3 is insoluble in water
- will not show reactivity immediately

even tho it is high up enf in reactivity series such dat it will react w/ acid

Question 6

why aluminium used, food wrapper?

Answer 6

has protective layer (Al2O3)
- will not rust

Question 7

how cause aluminium react?

Answer 7

1. scrape, sandpaper
2. Place into acid, long time

Al2O3 -> insoluble in water, amphotheric. Will react w/ acid slowly.

https://docs.google.com/document/d/1Ep_FO9CxYSFbxmf3Zqg9mgm9NNyt2enpfMDr49gufrU/edit?tab=t.0 page 15

Question 8

G1 metals/K, Na, Ca displacement why dont use/why bubbling?

Answer 8

1. Soln G1 metal placed in, (aq)
2. Sodium react w/ water violently, high reactivity

Question 9

thermal decomposition

which metal easier decompose?

Answer 9

Less reactive metal, easier metal carbonate decompose

sulfate, nitrate, carbonate also decompose
not only carbonate

Question 10

Why Potassium, Sodium, G1 metals formed compounds nvr thermally decompose

Answer 10

no reaction
1. K, Na vry reactive
2. (other anion) thermally stable
3. bonds formed vry strong
4. req lot of heat energy, break
5. G1 metals dont thermally decompose

1. K, Na bonds super strong coz vry reactive.
2. It desperately clings onto other anion
3. ionic bonds dosent end up breaking and thermally decomposing

sulfate, nitrate, carbonate also decompose
not only carbonate

Question 11

1. CaO (s) + C(s) ->
2. 2CuO (s) + C (s) ->

Answer 11

1. reduction by carbon reaction does not happen, C less reactive, Ca
2. reduction happens (Co2 (g) + 2Cu (s)), C more reactive, Cu

works the same way, displacement does.
C (s) is always the displacer.

**eqn: ** metal oxide + carbon -> co2 + 2cu(s)

Question 12

1. CaO (s) + H2 (g) ->
2. CuO + H2 (g) ->

Answer 12

1. reduction by hydrogen gas does not happen, H2 less reactive, Ca
2. reduction happens (H2o (g) + 2Cu (s)), H2 more reactive, Cu

works the same way, displacement does.
H2 (g) is always the displacer.

**eqn: ** metal oxide + h2 -> h2o(l) + metal

Question 13

does silver carbonate decompose?

Answer 13

yez
1. decompose, silver oxide Ag2O + co2

2. 2Ag2o unstable, decompose further -> 4Ag + o2

Question 14

.

reactivity series
list out all metals that thermally decompose

form what products?

Answer 14

all except potassium, sodium

carbonate decomposes, form metal oxide + co2

metal carbonate -> metal oxide + carbon dioxide

Question 15

top 4 reactive metals in reactivity series…
1. desc how react in water

Answer 15

Potassium: explosive, (giving out bright flame)
Sodium: fast
Calcium: readily
Magnesium: slow

Question 16

how determine state symbols if not given

Answer 16

1. look for struct
2. i.e. SMS = low mp, bp, (g)
3. i.e. GILS = high mp, bp (s)

Question 17

metal coating
vs
sacrificial protection

advantage, disadvantage

Answer 17

metal coating:
nicer finish (aesthetics)
small hole for h2o, o2 enter, ineffective

sacrificial protection:
no need coat entire surface, need replace metal once in a while

Question 18

uses of stainless steel, mild steel, aluminium

Answer 18

stainless: surgical instruments/ stainless steel cutlery
mild: car bodies/machinery
aluminium: soft drink cans

Question 19

what does acid rain do?

Answer 19

acid rain
1. corrode limestone struct, metal
2. kill aquatic life (acidic rivers)

Question 20

does industry commonly use pure metal? if not wat use?

Answer 20

no
use alloy

Question 21

iron react w/ steam eqn is…? (unique pt)

Answer 21

reversible
3Fe (s) + 4h2o (g) -> Fe3O4 + 4H2 (g)

iron and steam
fe3o4 is unique, containing both iron (II) and (III) ions

iron rusting
fe2o3 (iron III)

Question 22

reduction, metal, C eqn

Answer 22

metal oxide + carbon -> Co2 (g) + metal

metal BELOW C reduce

For extraction of pure metal

Metal is reduced.

Question 23

reduction, metal, H2 eqn

Answer 23

metal oxide + H2 (g) -> metal + water vapour

metal BELOW H+ reduce

For extraction of pure metal

Metal is reduced.

Question 24

Y reactive metal greater tendency displace less reactive metal

Answer 24

1. more reactive metal, greater tendency lose electrons
2. than less reactive metal
3. forming cations

Question 25

explain sacrificial protection

Answer 25

1. more reactive metal attach less reactive metal 2. more reactive metal oxidise, corrode first 3. e.g. zinc bars on hull on steel ships 4. replace regularly 5. less exp, replace entire steel struct

Question 26

explain galvanising

Answer 26

coating less reactive metal w/ zinc type of sacrificial protection coating dmg -> still sacrificial protection

Question 27

explain use alloys prevent rusting method

Answer 27

contain Nickel, Chromium, rust-resistant alloys i.e. stainless steel ## Footnote Ni, Cr cause Fe to not rust easily in stainless steel **only iron rust.**

Question 28

use protective layer prevent rust/oxidation

Answer 28

1. apply coat, paint 2. oil: machinery parts 3. metal coating: food cans 4. plastic coating: kitchenware

Question 29

what happens, rusting of iron

Answer 29

slow oxidation + exposed 2 water, oxygen in air, iron, form hydrated iron(III) oxide (rust)

Question 30

define rust

Answer 30

flaky red-brown substance

Question 31

rusting of iron chem formula

Answer 31

4Fe + 3O2 + 2xH2o -> 2Fe2O3.xH2o (s) iron + oxygen + water -> hydrated iron (III) oxide

Question 32

what increases rate of rusting

Answer 32

presence of sodium chloride, acidic env.

Question 33

which metals extracted by what method

Answer 33

**electrolysis, molten ore**: PSCMA **heating metal oxide w/ carbon // reduction w/ carbon**: ZITLHC **physical methods:** SGP

Question 34

ore

Answer 34

compounds, metals mixed w/ earth, rocks

Question 35

which metals rust?

Answer 35

ONLY IRON rest **corrode/oxidise**

Question 36

after CuO reduced by H2 (g) in a **hot** env., H2 (g) is continuously allowed to flow through until surrounding temp **cools** down why is that so?

Answer 36

prevent copper (II) react w/ H2o (g) in air forming CuO again as temp is high enf, reaction w/ moisture in air to occur

Question 37

what is magnesium fuse for in displacement reaction

Answer 37

provide energy, displacement reaction

Question 38

atomic size means...

Answer 38

atomic radii

Question 39

reduction need heat?

Answer 39

**SOME** need heat energy, reduce metal oxide -> metal

Question 40

metal another state besides (s)

Answer 40

**molten state** (l) only if stated.

Question 41

food cans often coated w/ ?

Answer 41

Tin after peel off, rate oxidation iron faster, Tin less reactive, Fe

Question 42

how does rust destroy iron?

Answer 42

rust formed, surface, iron, steel objects flaky substance, easily crumbles into powder, rust flakes off, more iron exposed, form rust metal destroyed completely eventually

Question 43

what slows down rust

Answer 43

boiling water

Question 44

displacement practical use

Answer 44

join tracks aluminium + iron (III) oxide displacement

Question 45

chrome-plating advantage compared to other metal

Answer 45

bright shiny finish

Question 46

how is rusting different from corrosion of other metals?

Answer 46

other metal's oxide layer form protective coating, prevent further reaction ## Footnote hydrated iron (III) oxide flakes off, exposes new layer of iron, causing it to rust as well

Question 47

in displacement explanation can write X displaced Y's ions?

Answer 47

**NO** for explanation, alw use element X displace Y ## Footnote **NEVER USE IONS. Will minus mark.**

Question 48

why alloys more corrosion resistant

Answer 48

alloys have some metals that will form protective layer against oxygen