I have been given $\ce{B2}$, $\ce{N2}$, $\ce{(O2)-}$ and $\ce{O2}$.
I have to short out which will undergo oxidation, reduction or both.
How can I tell it when reactants are not given?
I have been given $\ce{B2}$, $\ce{N2}$, $\ce{(O2)-}$ and $\ce{O2}$.
I have to short out which will undergo oxidation, reduction or both.
How can I tell it when reactants are not given?
You have to look at the possible oxidation states of the atoms involved. For instance, if you were given the molecule $\ce{F2}$, you should consider that fluorine has two possible oxidation states: 0 (in the $\ce{F2}$ molecule) and -1. Hence, $\ce{F2}$ can only undergo reduction. For the other molecules, you should use the same strategy: try yourself!
To find out which substance has gone oxidation or reduction, you have to check their oxidation nos. If the oxidation increases, the substance is oxidised, if it decreases, the substance is reduced. For eg. . Here, Sulfur is getting oxidised while Bromine is getting reduced.