Classification of a Solid!

We completed a Classification of Solids Lab in order to classify and identify common properties of a solid substance by uses techniques to check MP, conductivity, and solubility. With the results from these tests, we were able to fulfill the purpose of the lab.

The process began with placing; MgO, CoCl2, phenyl saline acid, benzoic acid, KBr, Charcoal, Sand, Fe, and Zn in plastic well plates.

First we examined the crystal structure of each solid. We then put a bit of each solid into different test tubes, and held them over bunsen burners measuring the melting point of the substances over a scale from less than 100 to greater than 300 degrees. Next we tested the solubility of each substance. We placed water, ethanol, and cyclohexane in a different sample of each substance. If the solid was completely dissolved we then tested for conductivity. Our test resulted in only two substances being conductive those being; KBr and CoCl2.

Our classification of the solids results were:

• MgO, CoCl2, and KBr for IONIC solids
• Phenyl Saline and Benzoic Acid for MOLECULAR
• Iron and Zinc are METALS
• Charcoal and sand as NETWORK solids

Questions:

1a. If solids are classified ionic solids would be soluble in water.
1c. Molecular solids would be soluble in organic solvents.
1d. Metals would conduct electricity when under pressure.
1e. Molecular solids would be slightly soluble in water and slightly conductive in that solution.

2. Due to a solid's slight electrical conductivity, white appearance, and MP at 80 degrees the solid would be classified as a molecular solid.

3. A network solid would be the classification of a high 1000 degree MP, insolubility and inability to conduct electricity. It would not be a metal seeing that if it was, it would be conductive.

4. K-metal, CaCO3-ionic solid, C8H18-molecular solid, HCL-ionic solid.

5a. Network solids are generally insoluble in water.
b.  Metals are generally ductile and malleable.
c.  Ionic solids generally nonvolatile.

This lab went well in comparison to the other labs we have completed. I really enjoyed it until I felt like I was going to pass out from the mixtures of smells, in particular the odor from the cyclohexane. :) In addition to making me light headed, the cyclohexane ruined the well plates by kind of decomposing the plastic… sorry :)