1.3 Oxidising and reducing agents Flashcards
Reduction
a gain of electrons by a reactant in any reaction
Oxidation
a loss of electrons by a reactant in any reaction
Redox reaction
reduction and oxidation take place at the same time
Oxidising agent
a substance that accepts electrons
Reducing agent
a substance that donates electrons
What elements act as reducing agents?
elements with low electronegativities tend to form ions by losing electrons and so act as reducing agents
What elements act as oxidising agents?
elements with high electronegativities tend to form ions by gaining electrons and so act as oxidising agents
What group in the periodic table has the strongest reducing agents?
group 1
What group in the periodic table has the strongest oxidising agents?
group 7
Compounds, group ions and molecules that act as oxidising or reducing agents
- hydrogen peroxide is a molecule that is an oxidising agent
- dichromate and permanganate ions are group ions that are strong oxidising agents in acidic solutions
- carbon monoxide is a gas that can be used as a reducing agent
Use of oxidising agents
Oxidising agents are widely used because of the effectiveness with which they can kill fungi and bacteria, and can inactivate viruses. The oxidation process is also an effective means of breaking down coloured compounds, making oxidising agents ideal for use as ‘bleach’ for clothes and hair.
The electrochemical series
the electrochemical series represents a series of reduction reactions. The strongest oxidising agents are at the bottom of the left-hand column of the series. The strongest reducing agents are at the top of the right-hand column of the series
Ion-electron equations
An ion-electron equation can be balanced by adding appropriate numbers of water molecules, hydrogen ions and electrons. Ion-electron equations can be combined to produce redox equations
