The four characteristics of titrimetric reactions are:
-The reaction must be simple and can be expressed by a chemical equation.
-The reaction should be fast.
-The reaction must undergo some alteration in the physical or chemical properties of the solution at the equivalence point.
-There must be an indicator available that can sharply define the endpoint of the reaction via any physical change.

Titrimetric reactions have four characteristics: they enable quantitative analysis, achieve reaction completeness at the equivalence point, use indicators to identify the endpoint, and require standardization of the titrant.