Chemistry Redox and Cells mistakes

when we have charge and know the equation at the fuel cell, what is the percent efficiency (can be charge or elec) what do we use

Using Q = n(e-) x F, from redox

Disadvantages of fuel cells in motor vehicles

expensive,

flammable as it is in hydrogen

Advantages of fuel cells

more energy efficient as directly chemical to electrical energy.

When balancing with an oxygen, and there’s multiple which do you use

The one which gives a stronger reaction/gradient

This is identified as a reducing agent, which version should you use to balance half equation ‘ 2Fe (s) or Fe(s)

Fe(s)

The electrolyte in the equation is

The ion in the question, and it needs to be bonded to something to be used as an electrolyte.

K + for OH-

If something is molten what is the state?

Liquid

What is the name of the fuel cell correspond to

The electrolyte

where does the co2 go in molten carbonate fuel cell? Out of cell?

No it gets recycled from the anode to the cathode

Why are the two half cells separated in fuel cell?

• to ensure electrons flow across the circuit and harness electrical energy

• To avoid reduction and oxidation to happen spontaneously and stopping the flow of electrons

Compare question layout

Define both things in context!

Then difference, then similarity.

Then link to context o

Green chemistry principles linking to fuel cells

Catalysis- electrodes contain catalysis which improve the rate of reaction and improve efficiency.

Design for energy efficiency- direct conversion of chemical to electrical energy.

Prevention of waste- no production of CO2 use of renewable feedstocks

02 produced via photosynthesis, to renewable

H2 electrolysis of H20. Energy provided by renewables

Green hydrogen

Green electricity and water resulting in green hydrogen

Issues with hydrogen

explosive and flammable

Colourless odorless

Storage and transport difficult due to the great volume it takes up, it requires high compression,

Differences between fuel cells and galvanic cells

Fuel cells are a continuous supply,

Porous electrodes

Secondary cells

rechargeable cells,

Electrical to chemical

Non spontaneous

Reluctant above oxidant

Discharge (like a galvanic)

Generates electricity, and is spontaneous

Chemical to electrical

Ph as H+ products would result in what?

H+ consumed means that the acidic nature of the cell would reduce and it would become more neutral hence increasing its pH

If substance solid can you break into ion for oxidising agent or reducing agent?

No, you must include the whole thing if not aqueous

Redox flow battery, how is this a hybrid of fuel and secondary cell

Because of a continuous supply of reactants, it is a fuel cell

Because it can be recharged,

Function of membrane

Transport electrons between electrodes

To prevent a spontaneous redox reaction

What would happen if the barrier was removed between two half cells

Current stops

Spontaneously react, (Release thermal E, confirm first so don’t say this till confirmed)

Stops thinning reductant, thing undergoing oxidation

Stops thickening oxidant, thing undergoing reduction

Why is the hydrogen half cell assigned a 0.00 value, what is its role in other voltages

It is a benchmark and reference, to compare other voltages

For example, Ni half cell E is lesser than the hydrogen half cell at -0.28, hence it is a stronger reducing agent than hydrogen and Ni 2+ is a weaker oxidising agent than 2H+.

Advantages of lead acid cell

Rechargeable, long life, reliable, high currency

Disadvantages of lead acid cell

Lead is poisonous, heavy, acid is corrosive, low energy density.