Answer:- (1) Co is the reducing agent because its oxidation number increases.
Explanations:- The given equation is:
[tex]2Co+3F_2\rightarrow 2CoF_3[/tex]
A reducing agent is the one that donate electrons. When electrons are lost from an atom then it's oxidation number increases. So,we could say that the element whose oxidation number increases, get's oxidized and works as a reducing agent.
In elemental state the oxidation number is zero. For the reactant side, cobalt and fluorine are in their elemental form and so the oxidation numbers for both of these is zero. On product side, the oxidation number of F is -1. Since, there are three F in the product and the over all charge for it is zero, the oxidation number of Co is +3.
Co is oxidized as it's oxidation number is increased from 0 to +3 and it loses three electrons. Fluorine is reduced as it's oxidation number decreased from 0 to -1 and it gain electrons.
Co is electron donor and F is electron acceporr. hence, Co is the reducing agent.
The half equations could also be shown as:
oxidation half equation:- [tex]Co\rightarrow Co^+^3+3e^-[/tex]
reduction half equation:- [tex]F_2+2e^-\rightarrow 2F^-[/tex]
reducing agent:- Co
Oxidizing agent:- [tex]F_2[/tex]
