Solubility Rules

Hey everybody!  Not a lot went on today in class, but we did learn a new topic, Solubility rules!  People who were present on Wednesday received class time to work on the Reaction Solubility 1 worksheet or the Solubility Rules Lab.  People who were absent on Wednesday completed the Solubility Rules Lab.

Homework:
  -Due tomorrow: Reaction Solubility 1
  -Due tomorrow: Solubility Rules Lab

The worksheet we received today has the common rules for the solubility of compounds.  These charts help identify if two compounds will form a precipitate or not.

Here is a chart that helps identify different ions that are usually soluble in water, which means that they don't form a precipitate.  I use the word usually because there are exceptions to the rule.  The right side of the chart lists the exceptions that make the compound insoluble.

Example problem:

KNO₃ (aq) + NaCl (aq) →  KCl (?) + NaNO₃ (?)

1. Using our solubility rules we know that all compounds with the K+ ion are soluble  which means it dissolves in water and is therefore aqueous (aq). 

2. Then, we can determine that all nitrates (NO₃-), are also soluble and aqueous (aq).

Final Answer:  KNO₃ (aq) + NaCl (aq) → KCl (aq) + NaNO₃ (aq)

This chart identifies ions that are usually insoluble in water, which means they do form a precipitate which is a sold.  Again, I use the word usually because there are significant exceptions listed on the right side of the chart.

Example problem:

AgNO₃ (aq)+ NaOH (aq) → AgOH (?) + NaNO₃ (?)

1.  Using the chart above, you can conclude that the (OH-) ion is insoluble, and in the reaction, it will not be combined with any ion that makes it soluble.  Therefore, we can conclude that (AgOH) will form a precipitate called a solid (s).

2.  Using the first chart, you can determine that all (NO₃-)compounds are soluble in water and aqueous (aq).

Final Answer:  AgNO₃ (aq)+ NaOH (aq) → AgOH (s) + NaNO₃ (aq)

Now you should have a clear understanding of the solubility rules and how to apply them!

THE NEXT SCRIBE WILL BE:.......Fabian J.