Unknown Compounds

Physically, the unknown compound was composed of white, grainy, crystal-like structures. The unknown was also odorless. From these observations, various physical and chemical testing was performed to determine properties of the unidentified compound.

A series of solubility tests were performed, as shown in Table 2, and revealed that the unknown compound was soluble in water, but not in Acetone or Toluene.

Because the compound dissolved in water, it is known that the compound is either polar or ionic3. Water is a polar substance, which maximizes its interactions with other polar molecules. Ionic substances also interact with and dissolve in water, because they can be considered an “extreme” case of polarity in which electrostatic forces hold atoms together. The interaction between water and the unknown compound can be described as “dissociation.” When a molecule is dissociated in a polar solvent, the anion of the molecule bonds with the solvent’s cation and vice versa4.

In

This result indicates that for every milliliter of water, .2 grams of the compound was dissolved; the science behind the test is that water is added in increments to determine how many mililiters of polar water molecules are necessary to break apart the polar or ionic bonds in a certain amount of solute.

A Litmus paper pH test of the compound dissolved in water revealed that the solution had a pH of 7. This indicated that the solution of water and dissolved compound was neutral, or neither basic nor acidic5. The result of this test is in agreement with the identified compound because there are no OH- cations or H+ anions in KCl. OH- ions tend to make substances basic, and H+ ions make compounds more acidic1. Additionally, this pH test affirmed that sodium hydroxide and hydrochloric acid testing were not necessary in assessing the compound’s