Question

What are Reducing Agents? And why are they used in chemical reactions?

Answer 1

see below

Explanation:

Chemical reducing agents are substances, neutral molecules or ions, that can easily oxidate themselves to a bigger oxidation number, reducing another substance.
they generally have a low Oxidation number (as `S^2-, I^-` or `H_2S` that give S), but `Cl^-` is a weak reducing, and `F^-` isn't at all.

Other usefull reducing agents are: some metals as Mg, Al, Zn and `H_2, NO_2^-, SO_2, SO_3^(2-), Sn^2+, Fe^2+`, ethanol .
Their force is tabelled in the standard reduction potentials (see figure) where they are in the right on the bottom
they are used to reduce oxydant substances, and they are usen in alimentary industries for prevention toware oxidation of foods and to conservation of food