Reduction for Dry Cell (1 Viewer)

[Lumix]

Is this reduction equation correct for dry cell?

2Mn4+ + 2O2- + 2H+ + 2e¯ 2Mn3+ + 3O2- + H2O

And does anyone know an easy way to memorise the chemistry of dry cell and silver oxide button cell?

 

[NewiJapper]

I didn't do the dry cell, but in terms of memorising, like ANYTHING else, just write it down, check, repeat. Write it down, check, repeat. Soon it will be imprinted in your brain.

 

[Lumix]

Sigh..., I have always hated rote learning but I guess this is probably the best method for this type of question.

 

[beardedwoman]

lol you don't. cram it the days before the exams for these tedious things.

 

[Mingsta]

I've got:

Long version: MnO2(s)+NH4*(aq)+H2O+e- Mn(OH)3(s) + NH3(aq)

Shortened version but still the same thing: 2Mn02 +2e- +H2O Mn2O3+2OH-

Just that they excluded the NH3 so that it would be simplified so the Hs have to go somewhere reasonable.

If you want the easiest one, that will still get you the marks if they ask for half reaction just do this one:

Mn4+ + e- Mn3+

 

[someth1ng]

Mn4+ + e- Mn3+

That's the cheapest shit I have ever seen...LOL

For oxidation, do the same for zinc

 

[someth1ng]

Overall Equation: Zn + 2MnO2 + 2H2O + 2NH4Cl --> ZnCl2 + 2NH3 + 2Mn(OH)3
Oxidation: Zn --> Zn2+ + 2e-
Reduction: Mn4+ + e- --> Mn3+

In all equations, I have omitted the states. Obviously, metals and the oxides/hydroxides are solid, all ions (ammonium/chloride) are aqueous and water is liquid.

 

[7eleven]

Dry cell
Cathode reduction
Mno2(s) + NH4+(aq) + H20(l) + e- → Mn(OH)3(s) + NH3(aq)

Anode oxidation
Zn (s) → Zn2+ (aq) + 2e-