Why are oxidation reduction reactions coupled?
1 Answer
Jul 31, 2018
Oxidation is the loss of electrons, while reduction is the gain of electrons. During a reaction, if a certain reactant gained electrons (get reduced), this would mean that another reactant lost those electrons (get oxidised).
For instance:
#bb2Mg(s) + O_2(g) -> bb2MgO(s)#
It's clear that Mg got oxidised (lost electrons) to become two
Look at those half-ionic equations:
#bb2(Mg(s) -> Mg^(2+)(aq) + 2e^(-))#
#O_2(g) + 2e^(-) -> O^(2-)(aq)#
Here, it is clear that the electrons cancel out each other to give you the balanced equation:
#bb2Mg(s) + O_2(g) -> bb2MgO(s)#
It is also clear that
