Which of the following statements does NOT describe Tollen's reagent?
A. Silver ammonia ion.
B. Oxidation of an aldehyde.
C. Reduction of an acid to aldehyde.
D. Reduction of silver ion to free silver.
Tollen's reagent contains [Ag(NH3)2]+, which is the silver ammonium ion. Oxidation of an aldehyde to an acid is accompanied by the formation of a silver mirror. The latter is the result of the reduction of the soluble silver ion to yield free silver metal.