What's a reducing agent?

Indicate whether each of the following chemical conversions REQUIRES an oxidizing agent (O), a reducing agent?

• Indicate whether each of the following chemical conversions REQUIRES an oxidizing agent (O), a reducing agent (R), or neither (N). a) NO31- NH3 b) PO33- PO43- c) AgCl Ag1+ + Cl1-

• Answer:

  a) NO3- --> NH3 Requires a reducing agent b) PO33- --> PO43- Requires an oxidizing agent c. AgCl --> Ag+ + Cl- There is no change in oxidation number. You figure this out by looking at the oxidation numbers of things in the equations. In the first one, the oxidation number of N decreases. Since this is a reduction, a reducing agent is required. In b), the oxidation number of P increases. Since this is an oxidation, an oxidizing agent is required. In c), there is no change in the oxidation numbers, so neither is required.