Chapter 19 Electrochemistry Flashcards
Define Oxidation Reduction Reaction
Reactions in which electrons transfer from one reactant to the other
Define Oxidation
The loss of electrons
Define Reduction
The gain of electrons
The INCREASE in oxidation state of an atom is ____________
Oxidation
The DECREASE in oxidation state of an atom is ____________
Reduction
What is the oxidation state rule for a free element?
Oxidation state = 0
What is the oxidation state rule for a monoatomic ion?
Oxidation state = its own charge
What is the oxidation state rule for the same of oxidation states of neutral molecules and ions?
Neutral molecule oxidation state = adds up to 0
Ion oxidation state = adds up to its charge
What is the oxidation state rule for metals in compounds in group 1A and 2A
Metal group 1A oxidation state = +1
Metal group 2A oxidation state = +2
What is the oxidation state rule for nonmetals H and O?
H oxidation state = +1
O oxidation state = -2
Assign oxidation states to the following... I) Cl2 II) Na+ III) KF IV) CO2 V) FeSO4
I) 0 II) +1 III) 0 IV) 0 V) -2
Assign oxidation states to the following... I) Ag II) Fe3+ III) CH4 IV) Cr2O7 2- V) ClO4 - VI) CaH2
I) 0 II) +3 III) C: -4, H: +1 IV) Cr: +6, O: -2 V) Cl: +7, O: -2 VI) Ca: -2, H: +1
Define Half-Reaction Balancing Method
A form of balancing redox reactions where you separate the overall equation into 2 half reactions
Define Balancing Redox Reaction
When you balance both the mass and charge of the redox reactions
What are the 2 half reactions for Half-Reaction Balancing Method?
Half for oxidation and half for reduction
When balancing ACIDIC solutions, what do you add to balance O and H?
Add H2O to balance O and H+ to balance H
When balancing BASIC solutions what is the additional step you must take?
Neutralize H+ by adding enough OH- to each H+ and add the same number of OH- ions to both sides
Define Oxidizing Agent
A substance that causes the oxidation of another substance
Define Reducing Agent
A substance that causes the reduction of another substance
Oxidizing Agent is ____________, _______ electrons, and its oxidation state __________
Reduced; gains; decreases
Reducing Agent is ____________, _______ electrons, and its oxidation state __________
Oxidized; loses; increases
In the following reaction which element is the Reducing Agent and which is the Oxidizing Agent? 4 Na (s) + O2 (g) --> 2Na2O (s)
Na : Reducing Agent
O: Oxidizing Agent
Define Electric Currents
The flow of electric charge
What are the 2 ways electric currents are involved with chemical reactions?
I) Certain chemical reactions can product electricity
II) Electricity can make certain chemical reactions (nonspontaneous reactions) happen that would not happen otherwise
Define Current
The number of electrons that flow through the system per second
The unit for Current is…
Ampere (A)
What are the 2 types of Electrochemical Cell types?
I) Voltaic (Galvanic) Cell
II) Electrolytic Cell
Define Voltaic (Galvanic) Cell
Electrochemical Cell that produces electrical current from a spontaneous chemical reaction