Topic 6- Redox Reactions Flashcards
What is oxidation the gain of?
What is oxidation the removal (loss) of?
What is reduction the gain of?
What is reduction the removal (loss) of?
Oxidation is the gain of oxygen
Oxidation is the removal (loss) of hydrogen
Reduction is the gain of hydrogen
Reduction is the removal (loss) of oxygen.
What are oxidation and reduction not only defined as?
What is oxidation also the removal (loss) of?
What two things can happen to the species?
What is reduction also the gain of?
What two things can happen to the species?
What is the definition of a redox reaction?
What does OIL stand for?
What does RIG stand for?
Not only defined as changes in oxygen and hydrogen
Oxidation is also the removal (loss) of electrons
Species will become more negative or less positive
Reduction is also the gain of electrons
Species will become more negative or less positive
When reduction and oxidation take place at the same time
Oxidation Is the Loss of electrons
Reductions Is the Gain of electrons.
What is the definition of oxidation states?
Describe oxidation states for atoms?
Describe oxidation states for cations?
Describe oxidations states for anions?
What are oxidation states in molecules?
Who will have the negative value?
What happens to electronegativity across a period and down a group?
What are oxidation states in complex ions?
What can many elements exist in more than one?
The number of electrons which must be added or removed to become neutral
Neutral already… no need to add any electrons
Need to add 1 electron to make the positive ion neutral
Need to remove 1 electron to make the negative ion neutral
In molecules, the sum of the oxidation states adds up to zero
The more electronegative species will have the negative value
Electronegativity increases across a period and decreases down a group
In complex ions, the sum of the oxidation states adds up to the charge
Many elements can exist in more than one oxidation state.
What are the three oxidation states for hydrogen?
What are the four oxidation states for oxygen?
What are the two oxidation states for fluorine?
What are the two oxidation states for chlorine?
What can the position of an element in the periodic table act as?
What values (oxidation states) do metals have in compounds?
What is the value usually that of?
What happens to the value of metals when there are several possibilities?
What values do non-metals usually have in compounds and what’s it based on?
What can their values be up to?
+1; except 0 for atom (H) and molecule (H2); -1 for hydride ion (H-)
-2; except 0 for atom (O) and molecule (O2); -1 in hydrogen peroxide (H2 O2); +2 in compounds with FO2
Always -1 ; except 0 for atom (F) and molecule (F2)
-1 ; except in compounds with F and O, where it has positive values
Can act as a guide for oxidation states
Have positive values in compounds
Value is usually that of the group number (Al +3)
When there are several possibilities the values go no higher than the group number
Mostly negative based on their usual ion
Can have values up to their group number.
What is often included in the name of a species to avoid ambiguity?
Eg what does Manganese (IV) Oxide show?
What is the definition of a reducing agent?
What does a reducing agent make something else do?
What does a reducing agent therefore donate?
What is the definition of an oxidising agent?
What does a oxidising agent therefore accept?
What are the four steps for balancing redox half equations?
The oxidation state is often included in the name of a species to avoid ambiguity
Shows that Mn is in the +4 oxidation state in MnO2
Something that reduces something else
A reducing agent makes something else gain electrons
A reducing agent donates electrons
An oxidising agent will oxide something else by causing it to lose electrons
An oxidising agent accepts electrons
- Work out formulae of the species before and after the change; balance if required
- If equation doesn’t balance for oxygen, add sufficient water molecules to one side
- Add sufficient H+ ions to one of the sides to balance the hydrogen
- Add electrons to one side of the equation so that the oxidation states balance.
What is the definition of a disproportionation reaction?
When something is simultaneously oxidised and reduced.
