B5 Oxidation, Reduction and Redox Flashcards
What is a redox reaction
a reaction in which one substance is reduced and another is oxidised
What is oxidation
increase in oxidation state
loss of electrons
gain in oxygen
loss of hydrogen
What is reduction
decrease in oxidation state
gain in electrons
loss of oxygen
gain in hydrogen
What is an oxidation state
the charge an atom of an element would have if it existed as an ion in a compound
/ the number of electrons to be added or subtracted from an atom in a combined
state to convert it to elemental form
How do we assign oxidation states to a free element
0
How do we assign oxidation states to a simple monoatomic ion
charge on ion
How do we assign oxidation states to a group 1 or 2 and aluminium
: +1, +2 and +3 respectively
The sum of oxidation states of all atoms in a neutral compound is equal to what
0
The sum of oxidation states of all atoms in a polyatomic ion is equal to what
0
Define disproportionation
a redox reaction in which the same substance is both oxidised and reduced
3Cl2 + 6OH- → 5Cl
- ClO3
- 3 H2O
What is a reducing agent
a substance that reduces another substance [In reactions, reducing agent is oxidised]
What is an oxidising agent
a substance that oxidises another substance [in reactions, oxidising agent is reduced)
in compounds, what is the oxidation state of fluorine
-1
in compounds, what is the oxidation state of oxygen
-2
in compounds, what is the oxidation state of hydrogen
+1
