Electrochemistry Flashcards
When an atom has lost an electron, it is said to have been _____________
oxidized
When an atom has gained an electron, it is said to have been _____________
reduced
Since both reduction and oxidization reactions happen at the same time, they are commonly referred to as _______ reactions
redox
Mnemonic to remember which gains and losses
OIL RIG
Donates electrons and becomes oxidized.
reducing agent
Accepts electrons and becomes reduced.
oxidizing agent
elements that are __________ on the activity series are more likely to donate electrons
higher
elements that are __________ on the activity series are more likely to receive electrons
lower
Occur without the need of additional energy input, result in liberation of electric energy
Spontaneous reactions
Require the input of electrical energy to proceed
non-spontaneous reactions
The order of the activity series is based on the ____________ ___________ values of most metals from most negative to most positive
electrical potential
Useful in identifying red/ox agents
Oxidation number
the oxidation state of any pure element in its natural state is _________
zero
the oxidation number of a monatomic ion is equal to its ________
charge
the oxidation number of oxygen is ______ except in __________ where it is ______
-2, peroxides, -1
the oxidation number of hydrogen is ______ except in __________ where it is ______
+1, metal hydrides, -1
the oxidation number of halogens is always ______ unless they form compounds with oxygen (except fluorine its always ______)
-1
Alkali metals have an ON value of _______
+1
Alkaline metals have an ON value of _______
+2
the sum of oxidation numbers in a _________ molecule is always zero
neutral
the sum of oxidation numbers in a charged molecule is the ______________
charge of the molecule
Every redox reaction consists of a ______________ half and a _______________ half
oxidation, reduction
ALthough the conservation of mass is upheld, redox reactions must also conserve _____________
charges
A spontaneous redox reaction can be used to generate a flow of electrons called a ______________ or _________________ cell
galvanic, voltaic
______________ cells are used to harness the energy of a redox reaction. This is done by physically seperating the chemicals into two _____________
galvanic, half-reactions
The electrons generated by the _______________ half-reaction must flow through a _______________ before they can be used in the ________________ half-reaction
oxidation, conductor, reduction
Allows the flow of ions to prevent a charge build up and completes the circuit
Salt bridge
