Redox Flashcards
What is oxidation ?
Loss of electrons
What is reduction ?
Gain of electrons.
What is oxidation in terms of oxygen ?
Addition of oxygen.
What is reduction in terms of oxygen ?
Removal of oxygen
What is oxidation in terms of hydrogen ?
Loss of hydrogen
What is reduction in terms of hydrogen
Addition of hydrogen
What is the definition of a redox reaction ?
One substance is oxidised and another is reduced.
Give an example of a redox reaction.
Thermite reaction. Iron Oxide (III) + Aluminium - Iron + Aluminium Oxide.
Aluminium is oxidised.
Iron is reduced.
What is an oxidation state/ number ?
An oxidation number of an element in a compound is the charge that’s the element would have if the compound was fully ionic.
What is the oxidation state for simple ions and give examples.
The oxidation state is the charge of the ion
Na1+ has an oxidation state +1
Mg2+ has an oxidation state +2
What is the oxidation state for atoms in elements and give examples.
Oxidation state is always zero.
Fe, Na, Cl2 , O2
What is the oxidation state of compounds ?
For all compounds the sum of oxidation states of each atom must equal zero.
Na = +1 Cl = -1
NaCl=0
What is the oxidation state for complex ions ?
The sum of the oxidation numbers of the atoms is equal to the overall charge of the atom.
What is the oxidation state for all group 1 atoms ?
+1
What is the oxidation state for all group 2 atoms ?
+2
What is the oxidation state of Aluminium ?
+3
What is the oxidation state of fluorine ? (f-)
-1
What is the oxidation state for hydrogen (H+)
Usually +1 but -1 when bonded to a metal, Si or B
What is the oxidation state of oxygen (O2) ?
Usually -2 but -1 when bonded with peroxides.
When does the oxidation state of a hydrogen ion change from +1 to -1 ?
When it is bonded to a metal, Si or B
When does the oxidation state of oxygen change from -2 to -1.
When bonded with peroxide’s.
What happens to the oxidation number during oxidation ?
It increases
What happens to the oxidation number during reduction ?
It decreases.
What is an oxidising agent ?
Accepts electrons
What is oxidation in terms of electrons ?
Loss of electrons
What is reduction in terms of electrons ?
Gaining electrons
What is a reduction agent?
Donates electrons
