# Conjugate Theory and Redox

I'm trying to apply conjugate theory, which I can apply very well to acids/bases, to redox. Can you verify my logic, which I have broken down below?

1) I know that solid sodium is a strong reducer.

2) I know this because solid sodium when placed in water reacts violently, forming, among other products, sodium ion.

3) Reducers are oxidized. Reducers lose electrons. Correct; $\ce{Na^{+}}$ is the product of placing solid sodium in water.

4) So in this half-reaction: $\ce{Na<=>Na^{+} +e^-}$, sodium is the reducer. $\ce{Na^{+}}$ is the conjugate oxidizer.

5) Oxidizers are reduced. Oxidizers gain electrons.

6) Because sodium is a strong reducer, which means it has a strong tendency to be oxidized, or a strong tendency to lose electrons, its conjugate oxidizer must be weak. Oxidizers are reduced; oxidizers gain electrons. The potential for $\ce{Na^{+}}$ to gain the electron that $\ce{Na}$ just lost must be small, or $\ce{Na}$ would not be a good reducer.

7) Therefore, a strong reducer's conjugate oxidizer must be weak.

8) Likewise, a strong oxidizer's conjugate reducer must be weak.

9) Likewise, a weak reducer's conjugate oxidizer must be strong.

10) Likewise, a weak oxidizer's conjugate reducer must be strong.

Also, if anyone could point me to a good reference on gaining insight into redox, tha would be great!

And while we're on the topic of redox, what's the mechanism for this reaction? Are both bonds cleaved homolytically? I see how the nucleophilic chlorines attack the electrophilic hydrogens but how's the bond broken?

$\ce{H_2 + Cl_2 ->2HCl}$

• The $\ce{HCl}$ formation reaction is generally a radical chain reaction, triggered e.g. by light, and not a redox reaction. The key here is to split the $\ce{Cl2}$ (e.g photo-chemically), then the obtained free radicals induce a chain-reaction with elementary steps like $\ce{Cl + H2 -> HCl + H}$ or $\ce{H + Cl2 -> HCl + Cl}$ The two gas mixed is more or less inert in total darkness.
• The formation of Hydrogenchloride from the elements is still a redox reaction, even if its mechanism is a radical one. In one of the reactions $$\ce{H. +Cl2 <=> [HCl2]. <=> HCl + Cl.}$$ The oxidation state of hydrogen is increased while the oxidation state of chlorine is decreased. – Martin - マーチン Jun 4 '14 at 4:05