Insolubility and Solubility

Mr. Liberman started off class today by first reviewing the rules of solubility and insolubility. First off, we restated what those words mean: something is soluble if it is able to dissolve in water, and something is insoluble if a precipitate forms in water. Then Mr. Lieberman explained that the lab that we did yesterday was the basis on which we were eventually going to base the solubility of certain compounds off of. This will include compounds that are commonly found around us and whether they are soluble or not, but it is not that black and white. There are some compounds such as silicate (SiO3) that is insoluble unless it contains the ions of K+ and Na+. There are many more examples like this.

To make things more interesting, Mr. Lieberman did the Lead Iodide experiment to show that certain compounds are always soluble (NO3), and therefore, you are able to identify the solids in a reaction. See Video Below:

This reaction is of Lead and Iodine. This solid had to form between these two elements because NO3(nitrate) mixed with any other element is soluble.

Since Lieberman was in a good mood, after explaining all of this, he let us work on the lab and the worksheets we got. Everybody was working until the bell rang and class ended. That was it for the day. The next scribe is....

Kaitlin S.

Lots of Reactions

In class today, we started a lab with many different sodium and nitrate groups, totaling 48 reactions. Why would we do that many, you ask? Well it has to be either:

a) Mr. Lieberman likes to make us do a ridiculous amount of writing and balancing equations

b) To help us formulate rules on formation of precipitates.

or c) All of the above

I'm Gonna go with C.

To start off, we put various solutions containing water and a Sodium Ion in each column. Then, we added a Nitrate solution to each of those, receiving varying results:

Some did absolutely nothing, leaving a clear liquid behind.

Others changed colors, but no precipitate formed.

Still others formed either a cloudy or completely solid precipitate, meaning that a reaction occurred.

And a couple did this:

Just kidding. But still, it was exciting. Here are the real results:

And my data table, if you can read it:

And the post lab is the real fun part: we have to write chemical equations for EVERY SINGLE PRECIPITATE! Both molecular and net ionic. For example, the molecular equation would be: 3Na₂SO₃+2Al(NO₃)₃ yields Al₂（CO₃）₃+6NaNO₃ and the net ionic equation would be: 2Al³⁺+ 3CO₃² yields Al₂(CO₃)₃. And repeat. About 20 times. Just a thrilling homework assignment. Oh, and by the way, for those who can't realize it yet: NaNO₃ is a product for every single molecular reaction, and always dissolves.
Thank you for reading my post. I hope you all do wonderful on your labs now. Now, the next scribe will be:.............................................

Ben A.

Keeping Balancing Equations Cool Like They're Going Out of Style

During Friday's class, we went even deeper into balancing equations. So deep that many people would consider it impossible in anyway shape or form. Specifically, we discussed Molecular Equations, Complete Ionic Equations, and Net Ionic Equations.

Molecular Equations

• Molecular Equations show the overall stoichiometry of the equation, but not the actual forms of the substances
• (Example): KCl+AgNO3------------>KNO3+AgCl

Complete Ionic Equations

• Complete Ionic Equations represent, as ions, all substances that are strong electrolytes
• Ionic Compounds dissociate in water
• Spectator Ions are ions that don't react; spectator ions are still included in Complete Ionic Equations
• (Example): K(^+)+ Cl(^-)+NO3(^-)------------>AgCl+K(^+)+NO3(^-)

Net Ionic Equations

• Includes only those ions undergoing a charge (spectator ions are NOT included)
• Net Ionic Equations are only written if a solid is formed
• (Example): Cl(^-)+Ag(^+)------------->AgCl(s)

NOTE: Molecular Equations, Complete Ionic Equations, and Net Ionic Equations are all Double Replacement Reactions

After we deciphered Molecular Equations, Complete Ionic Equations, and Net Ionic Equations, we proceeded to work on our newest worksheet (Net Ionic Equation Worksheet). Here are some tips in completing this worksheet:

1. To find the Molecular Equation, balance the equation given
2. To find the Complete Ionic Equation, seperate ions from compounds (include charges)
3. If a reaction isn't seen, or there is no solid, a Net Ionic Equation isn't needed

We proceeded to work on the Net Ionic Equation Worksheet for the rest of class.

On Monday, we will be doing a series of 48 reactions. The reactions will help establish rules regarding what we talked about on Friday. Furthermore, there is a WebAssign due Monday, on section 4.2 (Precipitation Reactions).

Stay thursty, my friends.