Chapter 9: Electric Cells Flashcards
What is reduction?
A process in which electrons are gained; a decrease in oxidation number.
What is oxidation?
A process in which electrons are lost; an increase in oxidation number.
What is an oxidizing agent?
A substance that gains or removes electrons from another substance.
What is a reducing agent?
A substance that loses or gives up electrons to another substance in a redox reaction.
What is corrosion?
An electrochemical process in which a metal reacts with substances in the environment, returning to an ore-like state.
What is metallurgy?
The process of extracting metals from ores, and refining them.
LEO say GER
Loss of Electrons is Oxidation
Gain of Electrons is Reduction
What is a half reaction?
The representation of a reaction in two parts, each part shows what happens to only one of the reactants.
How must both half reactions be balanced?
By mass (same number of element symbols on both sides) and by charge (same total charge on both sides)
What is an oxidation number?
A positive or negative number corresponding to the apparent charge that an atom in a molecule or ion would have if the electron pairs in covalent bonds belonged entirely to the more electronegative atom.
Assigning oxidation numbers.
- Atoms in elements: 0
- Hydrogen: 1+, Hydrides: 1-
- Oxygen: 2-, Peroxides: 1-
- Monatomic ions: Charge on ion.
Redox spontaneity rule.
A spontaneous redox reaction occurs only is the OA is above the RA in a table of relative strengths of oxidizing and reducing agents.
May be either oxidizing or reducing agents.
H2O, Fe2+, Cu+, Sn2+, and Cr2+.
Electric cell.
A device that continuously convert chemical energy into electrical energy.
Battery.
A group of two or more electric cells connected in series.
