Precipitation Reactions: Crash Course Chemistry #9

Precipitation is stuff falling out of other stuff: water falling out of the sky, solids falling out of solution.

Some ionic compounds can overcome even the dissolving power of water, and when they form through reactions in solution, they fall out as a solid precipitate.

The key to understanding what just happened here is that both of the compounds are ionic.

We're left with silver chloride. Just process of elimination.

Unlike salt though it's not very soluble in water.

There are special ways to write and balance them as equations.

If we wanted to get the silver out of solution, how much salt would we need?

Silver nitrate and a compound called silver sulfadiazine were used to disinfect wounds in World War I, before antibiotics were discovered.

Some people even take colloidal silver, basically silver particles in a liquid suspension, as a kind of general health booster.

In our case, there's another type of reaction necessary called a redox reaction. Redox is short for reduction-oxidation and that is what we'll be talking about next time.

We discussed what defines precipitation reactions, and how you can determine what precipitants they form.

We also learned how to write precipitate reaction equations.

We calculated a molar mass equation to figure out how much of a reactant we need to produce a desired amount of precipitant.

Our chemistry consultant is Dr. Heiko Langner.

This episode was filmed and directed and edited by Nicholas Jenkins with sound design by Michael Aranda.