area 51

Zinc carbon dry cell anode half rxn

Zn(s) -> Zn²⁺(aq) + 2e⁻ 

Zinc carbon dry cell Cathode half rxn

2MnO₂(s) + 2NH₄⁺(aq) + 2e⁻ -> Mn₂O₃(s) + 2NH₃(aq) + H₂O(l)

Zinc carbon dry cell full rxn

Zn(s) + 2MnO₂(s) + 2NH₄Cl(aq) -> ZnCl₂(aq) + Mn₂O₃(s) + 2NH₃(aq) + H₂O(l) 

Zinc carbon dry cell Primary or secondary

Primary

Zinc carbon dry cell voltage

1.5

Zinc carbon dry cell advantages

Low cost

Zinc carbon dry cell Weaknesses

Ammonia leaks, therefore limited shelf life

Zinc carbon dry cell

Single voltaic cell, AAA to D

Alkaline dry cell anode half rxn

Zn(s) + 2OH-(aq) → Zn(OH)₂(s) + 2e-

Alkaline dry cell Cathode half rxn

2MnO2(s) + 2H2O(l) + 2e- → 2MnO2(s) + 2OH-(aq)

Alkaline dry cell full rxn

Zn(s) + 2MnO2(s) + H2O(l) -> ZnO(s) + 2MnO(OH)(s)

Alkaline dry cell Primary or secondary

primary

Alkaline dry cell weaknesses

primary, non rechargable

Alkaline dry cell advantages

no ammonium or ammonia, therefore no leakages

Zinc is powdered, more surface area and faster rxn

Alkaline dry cell voltage

1.5

Alkaline dry cell

alkaline pastee, zinc powdered

silver oxide anode rxn

Zn + 2OH- → Zn(OH)2 + 2e^-

silver oxide cathode rxn

Ag2O(s) + H2O(l) + 2e- → 2Ag(s) + 2OH-(aq)

silver oxide full rxn

Ag₂O + H₂O + Zn → 2Ag + Zn(OH)₂

silver oxide primary or secondary

primary

silver oxide voltage

1.55

silver oxide advantages

longer shelf lifee, constant V at low current

silver oxide weaknesses

higher cost, limited energy capacity, primary

silver oxide

NaOH, constant V at low current, vs KOH, constant V at high current

lead acid anode half rxn

Pb + HSO4- → PbSO4 + H+ + 2e-

lead acid cathode half rxn

PbO2(s) + 3H+(aq) + HSO4-(aq) + 2e- → PbSO4(s) + 2H2O(l) 

lead acid net rxn

Pb(s) + PbO₂(s) + 2H₂SO₄(aq) → 2PbSO₄(s) + 2H₂O(l)

lead acid primary or secondary

secondary

lead acid advantages

large voltage, long shelf life, operates well at low temperature, energy transfer

lead acid voltage

6 cells, 2 V each, 12 in total

lead acid disadvantages

heavy weight, limited cycle life, toxic materials, low energy density (goes down over time)

lead acid

starting engines, spongy/poroud lead

NiCd anode half rxn

Cd(s) + 2OH⁻(aq) → Cd(OH)₂(s) + 2e⁻

NiCd cathode half rxn

NiO(OH)(s) +H2O(l) + e- -> Ni(OH)2(s) + OH-(aq). 

NiCd net rxn

Cd + 2NiO(OH) + 2H2O → 2Ni(OH)2 + Cd(OH)2 + 2e-

NiCd secondary or primary

secondart

NiCd volt

1.2

NiCd disadvantages

expensive

NiCd advantages

long shelf life, constant V, hard to damage

NiCd

ribbons of anode and cathode separated by material that allows ions too pass-through

Lithium advantages

lighter, higher capacity, lasts longer

Lithium metal

lightest metal, lowest standard reduction potential

Lithium primary or secondary

primary

Lithium volt

1.5-3.5

Lithium disadvantages

also farming ethicalities, primary

new fuel cell anode rxn

2H₂ → 4H⁺ + 4e⁻

new fuel cell cathode

O2 + 4H+ + 4e- → 2H2O 

new fuel cell net rxn

2H₂ + O₂ → 2H₂O

old fuel cell anode half rxn

2 H₂ (g) + 4 OH^- (aq) ->  4 H₂O (l) + 4 e^-

old fuel cell cathode

O2 (g) + 2 H2O (l) + 4 e- -> 4 OH- (aq)

old fuel cell net rxn

2H₂ + O₂ → 2H₂O

new fuel cell advantages

no corrosive chemicals, lighter, smaller, same net (H2O)

old fuel cell disadvantages

corrosive materals

new fuel cell

proton exchange membrane between electroodes, acidic solutino replaces KOH salt bridge