FC12: Oxidation States Flashcards
What is oxidation
loss of electrons, gain of oxygen
What is reduction
gain of electrons, loss of oxygen
What does an increase/decrease in oxidation number mean?
oxidation/reduction
What oxidation number do uncombined elements have
zero
what oxidation number do monatomic ions have
same size and sign as the charge of the ion
What is the fixed O.N. of combined hydrogen
+1, except in hydrides where it is -1
What is the fixed O.N. of combined oxygen
-2, except in peroxides where it is -1, when bonded to F where it is +2
What is the fixed O.N. of group 1 elements in compounds
+1 usually
What is the fixed O.N. of fluorine
-1 usually
What must the sum of the O.N.s in a formula equal
the charge of the formula
What does the roman numeral immediately after the part of the compound’s name mean?
The O.N. of the element that can have a variable O.N.
When given the systematic name of a polyatomic ion, and you need to work out the formula, what sign must the sum of the O.N.s for the formula to be correct for atoms
negative
write out a half equation for sodium being oxidised from an ON of 0 to and ON of +1
Na -> Na+ + e-
What is a redox reaction
When the reactants undergo a change in their oxidation states in a reaction
