2Li + CI2 -> 2LiCI

2Na + CI2 -> 2NaCI

2K + CI2 -> 2KCI

Chemical Properties Group 1

Size increase Reaction with 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)

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

4Li + O2 -> 2Li2O

4Na + O2 -> 2Na2O

4K + O2 -> 2K2O

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 sol Reactivity 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)

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 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 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)

Thermodynamics measurement

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 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

Electrochemical Series - 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

Electrochemical Series

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 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

Electrochemical Series 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 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