How strong is the reducing power of sodium hypophosphite, and what is its reduction mechanism? These are questions of great concern to technicians engaged in chemical nickel surface treatment and water-reducing agent production. During the redox reaction of sodium hypophosphite, electrons are gained, lost, or shifted. As we all know, phosphorus has a +1 oxidation state, easily losing electrons. Therefore, after a reduction reaction, its oxidation state increases, and it is oxidized, hence the name "reducing agent," and its product is called an oxidation product. Below, we summarize some rules of redox reactions for your reference.

I. Rules of Reduction Oxidation State: Elements in their highest oxidation state exhibit only oxidizing properties; elements in their lowest oxidation state exhibit only reducing properties; elements in intermediate oxidation states exhibit both oxidizing and reducing properties.

II. Order of reducing power of ions: S2- > SO3(2-) > I- > Fe2+ > Br- > Cl- > F-2

III. Classification of common reducing agents:

1. Low-valence oxygen-containing compounds: Sodium phosphite, CO, SO2, H2SO3, Na2SO3, Na2S2O3, NaNO2, H2C2O4, sodium borohydride, sodium hypophosphite, and organic compounds containing -CHO: aldehydes, formic acid, formate salts, certain formate esters, glucose, maltose, etc.

2. Active metallic elements: Na, Mg, Al, Zn, Fe;

3. Low-valence metal ions: Fe2+, Sn2+;

4. Certain non-metallic elements: C, H2, S;

5. Non-metallic anions and their compounds: S2-, H2S, I-, HI, NH3, Cl-, HCl, Br-, HBr;

Sodium hypophosphite is an oxygen-containing inorganic reducing agent with strong reducing power, good water solubility, and environmental friendliness. It can undergo redox reactions with high-valence metals such as nickel, copper, zinc, gold, silver, mercury, nickel, chromium, and cobalt.