Chapter 7 (Redox Reactions) Flashcards
What is the oxidation state of elements?
Zero
What is the oxidation state on simple molecules?
The charge on the ion
What does the total oxidation state equal?
The overall charge on the species
What is the negative ion in complex ions/molecules?
The more electronegative element
What is the charge on H (majority)?
+1
What is the charge on oxygen (majority)?
-2
What is oxidation?
A loss of electrons
What is reduction?
A gain of electrons
What is the oxidising agent?
The species that removes electrons from another.
What is the reducing agent?
The species that gives electrons to another.
What is a disproportionation reaction?
A species that is simultaneously oxidised and reduced.
What are the steps for writing half equations?
1) Calculate oxidation states on each side of the equation.
2) Balance the element changing oxidation state.
3) Sort electrons. If oxidation state becomes more negative then electrons are gained. If oxidation state becomes more positive then electrons are gained.
4) Sort out hydrogens. For every hydrogen gained or lost, add/remove one H+ ion.
What are spectator ions?
Species that do not take part in the reaction.
How are variable oxidation states shown?
Roman numerals in brackets
What does the ending ‘-ate’ mean in ions?
Has oxygen and negative charge.
