The document discusses the reactivity and electrochemical series of group 1 alkali metals lithium, sodium, and potassium. While lithium has the most negative standard reduction potential, indicating it is most easily oxidized, potassium is the most reactive when reacting with water and acids due to lower kinetic barriers. The electrochemical series is a thermodynamic measurement based on standard potentials, while the reactivity series considers reaction kinetics. Thus, there is a correlation but not perfect agreement between the two series.

1. 2Li + CI2 -> 2LiCI
2Na + CI2 -> 2NaCI
2K + CI2 -> 2KCI
Chemical PropertiesGroup 1
Size increase
Reactionwith water
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)
Chemicalreaction
2Li + 2H2O -> 2LiOH + H2
2Na + 2H2O -> 2NaOH + H2
2K + 2H2O -> 2KOH + H2
Reaction with oxygen Reactionwith 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
ReactivityGp 1
4Li + O2 -> 2Li2O
4Na + O2 -> 2Na2O
4K + O2 -> 2K2O

2. Reactivity Series
Reactivityseries
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 (REDOXreaction)
Reactive metaldisplace less reactive metalfrom 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 accordingto their ability to lose electron - form +ve ions
• Measure tendency of metals in losing electrons (Undergooxidation)
• Metals – lose electrons – form electropositiveions – Oxidation Process
Click here microscale Fe reduction
lithium
How fast rxn happen? (Kinetics)

3. ElectrochemicalSeries
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
Mg 2+ + 2e- ↔ Mg -2.37
Al3+ + 3e- ↔ AI -1.66
Mn2+ + 2e- ↔ Mn -1.19
H2O + e- ↔ H2+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- ↔ H2 0.00
Cu2+ + e- ↔ Cu+ +0.15
SO4
2-
+ 4H+ + 2e- ↔ H2SO3 + 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)
STRONG
Reducing Agent
WEAK
Reducing Agent
BOTTOM right
• Low ↓ tendency lose e
• F - → 1/2F2 + 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 oxidizingAgent
• 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)
Thermodynamics measurement

4. ReactivitySeries
lithium Li
Potassium > Sodium > Lithium
ElectrochemicalSeries
Reactivityvs ElectrochemicalSeries
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
Mg 2+ + 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

5. ElectrochemicalSeries - Thermodynamics measurement
M(s) → M+
(g) + e
∆Ha/kJ mol-1 ∆Hhyd/kJ mol-1
Li +161 +519 -499
Na +108 +494 -390
K +90 +418 -305
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
ElectrochemicalSeries
STD Oxidation potential
Reduced sp ↔ Oxidized sp Eθ/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 energeticallyfavourable
+∆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

6. ElectrochemicalSeries
STD Oxidation
potential
Reduced sp ↔ Oxidized sp Eθ/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 energeticallyfavourable
+∆H = NON spontaneous/favourable
+∆H = NON spontaneous/favourable
↓
Na → Na+ + e +Eθ
ReactivitySeries
Potassium > Sodium > Lithium Lithium > Potassium > Sodium
vs
Reactivityvs ElectrochemicalSeries
Lithium is above Potassium in electrochemicalseries
↓
Lithium is below Potassium in ReactivitySeries
↓
Due to kinetics factors/activationenergy, Rxn is slower
Potassium K
Sodium Na
Lithium Li