Unit 3 KA5 - oxidising + reducing agents Flashcards
what is an oxidation reaction?
a loss of electrons by a reactant
what is a reduction reaction?
a gain of electrons by a reactant
what is a redox reaction?
electrons being lost by one particle and gained by another
involves 2 half-reactions - oxidation + reduction
how can a redox equation be written?
1 - ion-electron equation for oxidation
2 - ion-electron equation for reduction
3 - balance the no. of electrons
4 - add oil + rig equations together
what is an oxidising agent?
accept electrons in a reaction and are themsleves reduced
what is a reducing agent?
donate electrons in a reaction and are themselves oxidised
do oxidising agents tend to be metal or non metal and why?
non metal because they accept electrons easily
do reducing agents tend to be non metal or metal and why?
metals because they lose electrons easily
what group is the strongest reducing agents?
1
what group is the strongest oxidising agent?
7
how does electronegativity affect whether an element is an oxidising or reducing agent?
elements with low electronegativities tend to form ions by losing electrons + so act as reducing agents
elements with high electronegativities tend to form ions by gaining electrons so act as oxidising agents
going up the electrochemical series, reducing agents become stronger/weaker
stronger
going down the electrochemical series, oxidising agents become stronger/weaker
stronger
how are more complicated half equations written?
1 - balance all elemtns except o and h
2 - add h20 if it is needed to balance the o atoms
3 - add H+ ions to balance h
4 - calculate total electrical charge on each side of the equation
5 - add electrons to balance equations
