Chapter 12 Flashcards
What occurs during single replacement?
Compound + element = new compound + new element
How does one predict if a single replacement reaction occurs?
One may look at the heat of formation and observe that heat of formation in the products is negative and larger than the heat of formation of the reactants
If an ion is found in the reactants and the products in the same place, they are called…
Spectator ions
In a net ionic equation what can be canceled out
spectator ions
What is a major driving force for chemical change?
The transfer of electrons
Where do electrons go during a transfer of electrons?
from substances that want them less to substances that want them more.
_________ is when something loses electrons
oxidation
What is the gaining of electrons called?
Reduction
If oxidation occurs, __________ must also occur too
Reduction
If reduction occurs, _________ must occur too
Oxidation
________ + ________ = Redox reactions
Oxidation, reduction (They can be combined since one can not occur without the other)
What are redox reactions?
Reaction in which oxidation and reduction occur in complementary ways
All single replacement reactions are ___________, but not all _________ are single replacement
Redox
What does the activity series compare in certain metals?
It compares the metal’s desire to lose electrons
When ___ is higher up on the activity series compared to ____, then a single replacement reaction can occur.
A, B
Formula= A+BX
The element that is in a molecule has to be lower than the one that is not
What are oxidation states
States assigned to each member of a formula while taking in mind each member’s degree to which electrons belong to them.
Elements with high __________ are given responsibilty for the electrons in a bond, ionic or covalent
Electronegativity
While referring to oxidation states, are electrons shared?
No, they belong to one element
What is another name for covalent bonds?
Molecular bonds
Where is the + or - sign in oxidation states?
Before the number, UNlike charges
For an _____________________, the sum of the oxidation states must be 0
Electrically neutral compound
For a polyatomic ion, the sum of the __________ must be equal to the __________
Oxidation states. Charge on the ion
If only an element or diatomic molecule, what would oxidation state be?
0
The oxidation state of a ______________ is the same as its charge
monatomic ion
What is the oxidation state of Fluorine?
-1
What is the oxidation state of Oxygen?
Usually -2, but sometimes -1 (In the presence of Fluorine)
What is the oxidation state of Hydrogen
+1
How do you tell if a redox reaction is occurring
If the oxidation states change
If the oxidation states remain the same in a reaction, then the reaction is not a _____________.
Redox reaction
What is a reducing agent?
An element that reduces another element in the reaction
What is an oxidizing agent?
It is the opposite of the reducing agent. It is an element that oxidizes another element in the reaction
If an element’s or molecule’s oxidation state reduces it can be considered the _________ if comparing to only one other molecule that changes its oxidation state
Oxidizing agent
The reducing agent is ________
oxidized
The ___________ is reduced
Oxidizing agent
What are combustion reactions synonymous with?
Burning
When a combustion reaction is finished, the elements in the burning fuel form compounds with the ________ and the responsibility for _______ changes
Oxidizing agent. Elections
The amount of heat released when 1 mol of fuel burns in called the __________
Heat of combustion
What is the symbol for the heat of combustion?
Delta H c (subscript)
What is one way a combustion reaction could occur? (Formula)
Hydrocarbon + O2 ———> CO2 + H2O
Methane = __________
Natural gas
T/F Oxidation states can be represented as fractions
True.
In C3H8, Carbon has an oxidation state of -8/3
