summary of Galvanic cells, Relation of current and potential difference to rate and equilibrium, Understanding of the processes and redox reactions taking place in galvanic cells, Standard electrode potentials, Electrolytic cells, Understanding the processes and redox reactions taking place in e...
Electrochemistry
Involves chemical reactions where chemical energy is converted to electrical energy or
electrical energy to chemical energy
Electrochemical process involves oxidation-reduction reactions or redox reactions where
electrons are transferred between substances.
REDOX REACTION:
● Transfer of electrons between elements/compounds
● Can be represented by half-reactions
○ oxidation
○ reduction
OXIDATION REDUCTION
A loss of electrons A gain of electrons
reducing agent⇒ substance that oxidized/loses oxidizing agent ⇒ substance that reduced/gains
electrons electrons (from another reactant)
an increase in oxidation number a decrease in oxidation number
Always at the anode Always at the cathode
A0 → A+ + e– oxidation number increase when A+ + e– → A0 oxidation number decreases when
oxides
TERM DEFINITION
Anode: the electrode where oxidation takes place.
Cathode: the electrode where reduction takes place
Electrolyte: a substance of which the aqueous solution contains ions OR a
substance that dissolves in water to give a solution that conducts
electricity. Salt of the compound.
Electrolysis: The chemical process in which electrical energy is converted to
chemical energy OR the use of electrical energy to produce a
chemical change.
, HOW TO BALANCE REDOX REACTION USING REDOX TABLE:
1. Identify the reactants
Zn(s) and H+(aq)
2. Underline reactants on the redox table
3. Draw arrows in direction of reaction
4. Write the oxidation and reduction half-reactions
Oxidation half-reaction: Zn → Zn2+ + 2e-
+ -
Red half-reaction: 2H + 2e → H2
Reduction happens Oxidation happens Reduction happens Oxidation happens
here here here here
Connects to the Connects to the Connects to the Connects to the
negative pole of the positive pole of positive pole of the negative pole of the
energy source energy source cell cell
Electrons of Electrons are Electrons of Electrons are
external circuit flow released to the external circuit flow released to the
towards it external circuit towards it external circuit
Is negative Is positive positive negative
GALVANIC CELL ELECTROLYTIC CELL
● a cell, chemical energy is converted into A cell, electrical energy is converted into chemical
electrical energy. energy.
● has self-sustaining electrode reactions.
- Spontaneous and Exothermic Non-spontaneous and Endothermic
- Chemical energy converted to electrical energy - Electrical energy converted to chemical energy
- Electrons ⇒ from the negative anode through the Requires a battery ⇒ a DC power source (one stays
external circuit to the positive cathode positive one stays negative)
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller bebeobinwa. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R60,00. You're not tied to anything after your purchase.
