7 oxidation reduction redox Flashcards
what is a redox reaction?
reduction and oxidation reaction occurring simultaneously
what is oxidation?
loss of electrons
what is reduction
gain of electrons
define oxidising agent
electron acceptor
define reducing agent
electron donor
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 rule for oxidation states of uncombined elements?
always 0
what is the rule for oxidation states of ions?
always equal to their charge
what is the rule for oxidation states of group 1 elements?
always +1
what is the rule for oxidation states of group 2 elements?
always +2
what is the rule for oxidation states of aluminium?
always +3
what is the rule for oxidation states of hydrogen?
+1
except in metal hydrides/bonded to F
what is the rule for oxidation states of chlorine?
-1
except when bonded to F or O
what is the rule for oxidation states of fluorine?
always -1
what is the rule for oxidation states of oxygen?
-2
except in peroxides or bonded to F, where it is -1
what is the acronym for remembering what order to assign oxidation states in?
Under
My
Face
Here’s
Our
Chin
what does ‘Under My Face Here’s Our Chin’ stand for?
Uncombined elements
Metals
Fluorine
Hydrogen
Oxygen
Chlorine
what does an increase in oxidation state of an element show?
oxidation
what does a decrease in oxidation state of an element show?
reduction
how do you tell if an element has been oxidised in an equation?
increase in oxidation number
how do you tell if an element has been reduced in an equation?
decrease in oxidation state
how do roman numerals show the oxidation state of a transition metal or an oxyanion
roman numeral = positive oxidation state
eg. Fe (III) = Fe3+
how do you balance half equations?
- balance any atoms (not O or H)
- balance O by adding water molecules
- balance H by adding H+ ions
- balance charges by adding electrons
