Reactivity 3.2- Redox reactions Flashcards
1
Q
Definition of oxidation
A
- Loss of electroons
- Increase in oxidation state
- Gain of oxygen
- Loss of hydrogen
2
Q
Definition of reduction
A
- Gain of electrons
- Decrease in oxidation state
- Loss of oxygen
- Gain of hydrogen
3
Q
Oxidising agents
A
Oxidising agents cause other substances to be oxidised and are themself reduced
4
Q
Reducing agents
A
Cause other substances to be reduced and are oxidised in the process
5
Q
Rules for labelling galvanic cells
A
- Oxidation occurs at the anode
- Reduction occurs at the cathode
- Electrons always flow from the side of oxidation to the side of reduction (anode to cathode)
- Salt bridge: cations to the cathode, anions to the anode
6
Q
Differences about electrolytic cells compared to galvanic cells
A
- Can be one cell
- Anode= positive
- Cathode= negative
- Turns electrical potential into stored chemical potential, compared to galvanic cells which turn chemical potential into electrical potential
7
Q
What are the characteristics of a fuel cell
A
- Do not store energy
- Continuous production of electrical energy from chemical energy
- Gaseous reactants
- Continuous supply of reactants
- Continuous removal of products
- Electrodes often act as catalysts
- Porous electrodes
8
Q
Compare discharging to recharging a secondary cell
A
Discharging:
* Is a voltaic/ galvanic cell
* Chemical potential— electricity
* Spontaneous redox reaction
Recharging:
* Electrolytic cell
* Electrical— chemical potential
* Non spontaneous reaction
