REDOX Flashcards
What is oxidation?
loss of electrons
what is reduction?
gain of electrons
what is an oxidizing agent?
electron acceptor
causes something to be oxidised
what is a reducing agent?
electron donor
causes something to be reduced
define oxidation state
the number assigned to atoms in a compound
to follow which elements are gaining or losing electrons
in a reaction
what is the oxidation state of uncombined elements (e.g., Mg, Na, O2, H2, Cl2)
0
What is the sum of all the oxidation states in a compound (e.g., NaCl)?
0
What is the oxidation state of a simple ion? (e.g., Mg2+)
the same as its charge
What is the sum of all the oxidation states in a complex ion (e.g., NH4+)
the same as its charge
What is the oxidation state of Hydrogen?
+1
What is the oxidation state of Hydrogen in metal hydride compounds?
-1
What is the oxidation state of group 1 metals?
always +1
What is the oxidation state of group 2 metals?
always +2
What is the oxidation state of Aluminium?
Always +3
What is the oxidation state of Oxygen?
-2
What is the oxidation state of Oxygen in peroxide compounds? (e.g., H2O2)
-1
What is the oxidation state of Fluorine?
always -1
What is the oxidation state of Chlorine?
-1
When can the oxidation state of Chlorine be a positive value?
in compounds containing F or O
an increase in oxidation state shows …
oxidation (becomes more positive)
a decrease in oxidation state shows …
reduction (becomes more -ve)
What is spectator ion?
ion which has not been oxidised or reduced in a REDOX reaction
Metals tend to undergo …
oxidation
Non-metals tend to undergo …
reduction
What are oxyanions?
negative ions that contain oxygen and another element
(indicated by the ending ‘-ate’)
e.g., SO42- (sulfate), CO32- (carbonate)
How do you balance for O in half equations?
Add water molecules
How do you balance for H in half equations?
Add H+
How do you balance for charges in half equations?
Add electrons
What is disproportionation?
The same atom undergoes oxidation and reduction at the same time
