Sunday, September 12, 2010

Eric's Salt Properties

As I was thinking about which household item I should choose, I immediately thought about salt (NaCl).  As with all matter, it has both physical and chemical properties.  I set out to explore what these were for salt.













All experiments in this project involving water use distilled water to insure accuracy.  Distilled water is free from ions, dissolved carbon, bacteria, and other contaminants.










Physical Property- A property that can be measured or observed without altering the composition of the substance.
The following are physical properties of sodium chloride.

1) Color- Sodium chloride appears clear to white.
2) Physical State- At room temperature, sodium chloride is a solid.










3) Crystallinity- Sodium chloride takes a cubic shape, with sharp edges.






















4) Solubility- Sodium chloride is soluble in water forming a homogeneous mixture.
video
5) Electrical Conductivity- Sodium chloride has the ability to conduct electricity, as seen in the video. (This video was too long to upload directly onto this website.  Please click on the link below and it will take you to youtube.com)

Eric's Electricity Conductivity Video


Chemical Property- A property in which a substance has the ability to undergo a chemical change.
The following are chemical properties of sodium chloride.

1) Odorless- Sodium chloride has no odor.




video
2) Changing flame color- When sodium chloride is heated using a Bunsen burner, the sodium emits a yellow-orange light.  In the same way, sodium gas is used in street lights and emits a very bright, yellow-orange glow.









3) pH- Sodium chloride has a neutral pH (about 7).







Pool pH test strips used in the experiment.
video






They are very similar! (Distilled water on left. Distilled water containing NaCl on right.)
4) Flammability – Sodium chloride is nonflammable.  Sodium chloride does not burn or sustain a flame on its own.
Note that I am wearing safety goggles!






video
5) Taste- Sodium chloride has a very distinctive and desired taste.  Used in many foods, sodium chloride tastes salty.  In this experiment, I eat salt-coated pretzels.
video

citation:
http://www.grandinetti.org/Teaching/Chem121/Lectures/IonicBonding/
http://www.pasco.com/chemistry/experiments/online/salt-solution-conductivity.cfm