What is the Difference Between Coprecipitation and Post Precipitation?

The main difference between coprecipitation and post-precipitation lies in the sequence of precipitation events and the composition of the resulting precipitates. Here are the key differences:

Coprecipitation:

1. Occurs when two or more substances come together to form a new substance.
2. Involves the simultaneous precipitation of soluble compounds in a solution.
3. The degree of contamination of the reaction is high.
4. For example, the separation of francium from other radioactive elements by co-precipitating it with caesium.

Post-precipitation:

1. Happens when a substance falls out of solution after the precipitation of the desired compound.
2. Involves the precipitation of a second, often related, substance upon the surface of an initial precipitate.
3. The degree of contamination is low.
4. For example, the formation of calcium oxalate after the precipitation of magnesium oxalate.

In summary, coprecipitation involves the simultaneous precipitation of two or more substances from a solution, resulting in their incorporation into a solid precipitate, while post-precipitation involves subjecting a primary precipitate to additional treatments or reactions, leading to the formation of new solid particles.

Comparative Table: Coprecipitation vs Post Precipitation

Here is a table comparing the differences between coprecipitation and post precipitation:

In summary, coprecipitation involves the removal of soluble compounds during a chemical reaction, often resulting in a high degree of contamination and an impure precipitate. In contrast, post precipitation occurs when an undesirable compound precipitates after the desired compound, typically leading to a lower degree of contamination and a potentially pure precipitate.