Reactivity Series

Question 1

H+ in reactivity series represent

Answer 1

acid

Question 2

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

Answer 2

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 3

which reactivity series metals react w/ steam + eqn

Answer 3

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 4

define displacement in metals

Answer 4

more reactive metal
displaces less reactive metal from
salt soln

Question 5

displacement experiement setup

Answer 5

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

Question 6

why aluminium removed from reactivity series?

Answer 6

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 7

why aluminium used, food wrapper?

Answer 7

has protective layer (Al2O3)
- will not rust

Question 8

how cause aluminium react?

Answer 8

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 9

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

Answer 9

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

Question 10

thermal decomposition

which metal easier decompose?

Answer 10

Less reactive metal, easier metal carbonate decompose

sulfate, nitrate, carbonate also decompose
not only carbonate

Question 11

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

Answer 11

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 12

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

Answer 12

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 13

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

Answer 13

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 14

does silver carbonate decompose?

Answer 14

yez
1. decompose, silver oxide Ag2O + co2

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

Question 15

.

reactivity series
list out all metals that thermally decompose

form what products?

Answer 15

all except potassium, sodium

carbonate decomposes, form metal oxide + co2

metal carbonate -> metal oxide + carbon dioxide

Question 16

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

Answer 16

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

Question 17

how determine state symbols if not given

Answer 17

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

Question 18

metal coating
vs
sacrificial protection

advantage, disadvantage

Answer 18

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 19

uses of stainless steel, mild steel, aluminium

Answer 19

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

Question 20

what does acid rain do?

Answer 20

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

Question 21

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

Answer 21

no
use alloy

Question 22

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

Answer 22

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 23

reduction, metal, C eqn

Answer 23

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

metal BELOW C reduce

For extraction of pure metal

Metal is reduced.

Question 24

reduction, metal, H2 eqn

Answer 24

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

metal BELOW H+ reduce

For extraction of pure metal

Metal is reduced.

Question 25

Y reactive metal greater tendency displace less reactive metal

Answer 25

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

Question 26

explain sacrificial protection

Answer 26

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 27

explain galvanising

Answer 27

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

Question 28

explain use alloys prevent rusting method

Answer 28

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 29

use protective layer prevent rust/oxidation

Answer 29

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

Question 30

what happens, rusting of iron

Answer 30

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

Question 31

define rust

Answer 31

flaky red-brown substance

Question 32

rusting of iron chem formula

Answer 32

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

Question 33

what increases rate of rusting

Answer 33

presence of sodium chloride

Question 34

which metals extracted by what method

Answer 34

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

Question 35

ore

Answer 35

compounds, metals mixed w/ earth, rocks

Question 36

which metals rust?

Answer 36

ONLY IRON rest **corrode/oxidise**

Question 37

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 37

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 38

what is magnesium fuse for in displacement reaction

Answer 38

provide energy, displacement reaction

Question 39

atomic size means...

Answer 39

atomic radii

Question 40

reduction need heat?

Answer 40

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

Question 41

metal another state besides (s)

Answer 41

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