IB Chemistry on Reactivity Series vs Electrochemical Series

1. http://lawrencekok.blogspot.com
Prepared by
Lawrence Kok
Tutorial on Reactivity Series vs Electrochemical
Series.

2. 2Li + CI2 -> 2LiCI
2Na + CI2 -> 2NaCI
2K + CI2 -> 2KCI
Chemical Properties Group 1
Size increase
Reaction with water
4Li + O2 -> 2Li2O
4Na + O2 -> 2Na2O
4K + O2 -> 2K2O
Click here video potassium in water
shell
2.1
2.8.1
2.8.8.1
2.8.8.18.1
Na
Li
K
Rb
lose electron easily
electropositive
Reactivity increase
Group 1 (Alkali Metal)
Chemical reaction
2Li + 2H2O -> 2LiOH + H2
2Na + 2H2O -> 2NaOH + H2
2K + 2H2O -> 2KOH + H2
Reaction with oxygen Reaction with halogen
Lithium – move slowly surface water – red flame
Sodium – move fast, hissing sound – yellow flame
Potassium – move fast, ignite - lilac flame
Turn red litmus blue- produce hydrogen gas
Solution of metal hydroxide/alkaline produced
Click here video sodium in water
Similar chemical property but diff reactivity
Lithium –burn slowly , red flame
Sodium – burn brightly, yellow flame
Potassium –burn very brightly, lilac flame
Kept in paraffin oil
Strong reducing agent
Reduce H+
ion to H2 gas
(losing e to H+
)
Oxidizing agent using potassium chlorate
Reactivity Gp 1

3. Reactivity Series
Reactivity series
Metals with water, acids, oxygen
Reactivity series
Non metal, Hydrogen and Carbon
Displacement rxn (H atom from H2O/HCI)
Reactive metal displace H atom from water
2K + 2H2O → 2KOH + H2
Ca + 2H2O → Ca(OH)2 + H2
Less reactive metal displace H atom from acid
Mg + 2HCI → MgCI2 + H2
Zn + H2SO4 → ZnSO4 + H2
Unreactive metal – No rxn with water /acid
Au + HCI →
Displacement rxn (REDOX reaction)
Reactive metal displace less reactive metal from its solReactivity series
Displacement rxn (O atom from less reactive)
Reactive metal displace O from less reactive metal
2Al + Fe2O3 → Al2O3 + 2Fe
Zn + PbO → ZnO + Pb
Displacement rxn (O atom from less reactive)
Reactive non metal displace O from less reactive metal
C + 2Fe2O3→ 3CO2 + 4Fe
H2 + CuO→ H2O + Cu
Displacement rxn (less reactive ions)
Reactive metal displace less reactive ions from its salt
Zn + CuSO4 → ZnSO4 + Cu
2Al + 3CuCI2 → 2AlCI3 + 3Cu
Reactive metal
Click here AI/CuCI3 displacement
Click here to view Flinn Scientific
Click here Iron extraction (Thermite)
• Metal arranged according to their ability to lose electron - form +ve ions
• Measure tendency of metals in losing electrons (Undergo oxidation)
• Metals – lose electrons – form electropositive ions – Oxidation Process
Click here microscale Fe reduction
lithium
How fast rxn happen? (Kinetics)

4. Electrochemical Series
STANDARD Reduction potential – H2 as std
Oxidized sp ↔ Reduced sp Eθ
/V
Li+
+ e- Li↔ -3.04
K+
+ e- K↔ -2.93
Ca2+
+ 2e- Ca↔ -2.87
Na+
+ e- Na↔ -2.71
Mg2+
+ 2e- Mg↔ -2.37
Al3+
+ 3e- AI↔ -1.66
Mn2+
+ 2e- Mn↔ -1.19
H2O + e- H↔ 2+OH-
-0.83
Zn2+
+ 2e- Zn↔ -0.76
Fe2+
+ 2e- Fe↔ -0.45
Ni2+
+ 2e- Ni↔ -0.26
Sn2+
+ 2e- Sn↔ -0.14
Pb2+
+ 2e- Pb↔ -0.13
H+
+ e- 1/2H↔ 2 0.00
Cu2+
+ e- Cu↔ +
+0.15
SO4
2-
+ 4H+
+ 2e- H↔ 2SO3 + H2O +0.17
Cu2+
+ 2e- ↔ Cu +0.34
1/2O2 + H2O +2e- ↔ 2OH-
+0.40
Cu+
+ e- ↔ Cu +0.52
1/2I2 + e- ↔ I-
+0.54
Fe3+
+ e- ↔ Fe2+
+0.77
Ag+
+ e- ↔ Ag +0.80
1/2Br2 + e- ↔ Br-
+1.07
1/2O2 + 2H+
+2e- ↔ H2O +1.23
Cr2O7
2-
+14H+
+6e- ↔ 2Cr3+
+7H2O +1.33
1/2CI2 + e- ↔ CI-
+1.36
MnO4
-
+ 8H+
+ 5e- ↔ Mn2+
+ 4H2O +1.51
1/2F2 + e- ↔ F +2.87
-ve
reduction
potential
+ve
reduction
potential
Compared to
H2 as std
Eθ
cell/Cell Potential = EMF in volt
EMF when half cell connect to SHE std condition
Std potential written as std reduction potential
TOP right
• High ↑ tendency lose e
• Li Li→ +
+ e
• Eθ
Li = +3.04V
• STRONG reducing Agent
•Oxi favourable (Eθ
=+ve)
TOP right
• High ↑ tendency lose e
• Li Li→ +
+ e
• Eθ
Li = +3.04V
• STRONG reducing Agent
•Oxi favourable (Eθ
=+ve)
STRONG
Reducing Agent
WEAK
Reducing Agent
BOTTOM right
• Low ↓ tendency lose e
• F -
1/2F→ 2 + e
• Eθ
F2 = - 2.87V
• WEAK reducing Agent
•Oxi NOT favourable (Eθ
=-ve)
BOTTOM right
• Low ↓ tendency lose e
• F -
1/2F→ 2 + e
• Eθ
F2 = - 2.87V
• WEAK reducing Agent
•Oxi NOT favourable (Eθ
=-ve)
WEAK
Oxidizing Agent
Strong
Oxidizing Agent
TOP left
• Low ↓ tendency gain e
• Li+
+ e Li→
• Eθ
Li= - 3.04V
• WEAK oxidizing Agent
• Red NOT favourable
(Eθ
=-ve)
TOP left
• Low ↓ tendency gain e
• Li+
+ e Li→
• Eθ
Li= - 3.04V
• WEAK oxidizing Agent
• Red NOT favourable
(Eθ
=-ve)
BOTTOM left
• High ↑ tendency gain e
• F2 + 2e 2F→ -
• Eθ
F2= +2.87V
• STRONG oxidizing Agent
•Red favourable
(Eθ
=+ve)
BOTTOM left
• High ↑ tendency gain e
• F2 + 2e 2F→ -
• Eθ
F2= +2.87V
• STRONG oxidizing Agent
•Red favourable
(Eθ
=+ve)
Thermodynamics measurement

5. Reactivity Series
lithium Li
Potassium > Sodium > Lithium
Electrochemical Series
Reactivity vs Electrochemical Series
Oxidized sp ↔ Reduced sp Eθ
/V
Li+
+ e- Li↔ -3.04
K+
+ e- K↔ -2.93
Ca2+
+ 2e- Ca↔ -2.87
Na+
+ e- Na↔ -2.71
Mg2+
+ 2e- Mg↔ -2.37
Al3+
+ 3e- AI↔ -1.66
Zn2+
+ 2e- Zn↔ -0.76
Fe2+
+ 2e- Fe↔ -0.45
Ni2+
+ 2e- Ni↔ -0.26
Pb2+
+ 2e- Pb↔ -0.13
Cu2+
+ 2e- ↔ Cu +0.34
Ag+
+ e- ↔ Ag +0.80
Lithium > Potassium > Sodium
Electrochemical Series - Thermodynamics measurement
↓
Eθ
value give – energetics feasibility of rxn- not rate/kinetics
↓
Rxn may be feasible,
but to slow to happen/no observable sign – Ea too high
↓
Measurement of voltage/potential using Std H2 Electrode
Reactivity – Kinetics
↓
How fast/metal with water and acid
↓
Due to low Ea – easier to react
↓
Potassium + water = faster/reactive
Lithium + water = slower/less reactive
Strong Correlation but may not be the same
↓
Li to Li+
ion more thermodynamically favourable than K to K+
ion
↓
K more reactive than Li in water/acid – due to kinetics factor

6. Electrochemical Series - Thermodynamics measurement
M(s) → M+
(g) + e
3 Steps rxn:
M (s) → M (g) ∆H = enthalpy of atomization
M (g) → M+
(g) ∆H = enthalpy of ionization
M+
(g) → M+
(aq) ∆H = enthalpy of hydration
Electrochemical Series
STD Oxidation potential
Reduced sp Oxidized sp E↔ θ
/V
Li Li↔ +
+ e +3.04
K K↔ +
+ e +2.93
Na Na↔ +
+ e +2.71
Li(s)
Li → Li+
(g)
∆Ha = +161
∆HI = +519 ∆Hhyd = - 499
Li+
(g) → Li+
(aq)
Li(s) → Li +
(aq) ∆H = +181
Li(s) → Li (g)
∆Ha = +90
K (s)
K (s) → K (g)
∆HI = +418 ∆Hhyd = - 305
K+
(g) → K+
(aq)
K(s) → K +
(aq) ∆H = +203
Na (s)
∆Ha = +108
Na(s) → Na(g)
∆HI = +494
K → K+
(g)
Na → Na+
(g)
∆Hhyd = - 390
Na+
(g) → Na+
(aq)
Na(s) → Na+
(aq) ∆H = +212
Lithium – least ∆H change
- Most energetically favourable
-∆H = spontaneous/favourable
-∆H = spontaneous/favourable
↓
Li → Li+
+ e +Eθ
Potassium – High ∆H change
- Less energetically favourable
-∆H = spontaneous/favourable
-∆H = spontaneous/favourable
↓
K → K+
+ e +Eθ
Sodium – Highest ∆H change
- Least energetically favourable
+∆H = NON spontaneous/favourable
+∆H = NON spontaneous/favourable
↓
Na → Na+
+ e +Eθ
Li Na
K
Lithium – Size smaller
↓
Easily hydrated → - ∆H favourable
↓
IE High – strong NC due to small size
Potassium– Size bigger
↓
Diff hydrated → +∆H non favourable
↓
IE Low – weak NC due to large size

7. Electrochemical Series
STD Oxidation
potential
Reduced sp Oxidized sp E↔ θ
/V
Li Li↔ +
+ e +3.04
K K↔ +
+ e +2.93
Na Na↔ +
+ e +2.71
Li(s)
Li → Li+
(g)
∆Ha = +161
∆HI = +519 ∆Hhyd = - 499
Li+
(g) → Li+
(aq)
Li(s) → Li +
(aq) ∆H = +181
Li(s) → Li (g)
∆Ha = +90
K (s)
K (s) → K (g)
∆HI = +418 ∆Hhyd = - 305
K+
(g) → K+
(aq)
K(s) → K +
(aq) ∆H = +203
Na (s)
∆Ha = +108
Na(s) → Na(g)
∆HI = +494
K → K+
(g)
Na → Na+
(g)
∆Hhyd = - 390
Na+
(g) → Na+
(aq)
Na(s) → Na+
(aq) ∆H = +212
Lithium – least ∆H change
- Most energetically favourable
-∆H = spontaneous/favourable
-∆H = spontaneous/favourable
↓
Li → Li+
+ e +Eθ
Potassium – High ∆H change
- Less energetically favourable
-∆H = spontaneous/favourable
-∆H = spontaneous/favourable
↓
K → K+
+ e +Eθ
Sodium – Highest ∆H change
- Least energetically favourable
+∆H = NON spontaneous/favourable
+∆H = NON spontaneous/favourable
↓
Na → Na+
+ e +Eθ
Reactivity Series
Potassium > Sodium > Lithium Lithium > Potassium > Sodium
vs
Reactivity vs Electrochemical Series
Lithium is above Potassium in electrochemical series
↓
Lithium is below Potassium in Reactivity Series
↓
Due to kinetics factors/activation energy, Rxn is slower
Potassium K
Sodium Na
Lithium Li

8. Acknowledgements
Thanks to source of pictures and video used in this presentation
Thanks to Creative Commons for excellent contribution on licenses
http://creativecommons.org/licenses/
Prepared by Lawrence Kok
Check out more video tutorials from my site and hope you enjoy this tutorial
http://lawrencekok.blogspot.com