The objective of this lab was to study a specific category of measurement, conductivity, that aids in the elementary differentiation of chemical and molecular compounds. To begin, molecular compounds are compounds that incorporate covalent bonding, or sharing of electrons between atoms, forming a very strong bond. On the other hand, ionic compounds are those in which two dipoles are attracted due to the difference of charge, positive and negative, as opposites attract.
Although the fact is sometimes argued, covalent bonds tend to be a stronger than ionic bonds due to the fact that the sharing of electrons is holding together the atoms- not just the attraction of two different charges, as in ionic compounds. There are many similarities and differences between ionic and molecular compounds. Molecular compounds generally are nonmetals bonded to nonmetals, brittle, weak, and/or soft, have low melting and boiling points, are poor conductors of heat and electricity, and tend to be insoluble in water. On the other hand, ionic compounds are bonded metals and nonmetals and are thus crystalline, hard or brittle solids, have high melting and boiling points, are good conductors of heat and electricity, and most are soluble in water. When both of these types of compounds are placed in an aqueous solution, an ionic compound will disassociate completely, meaning, the two atoms, both charged and thus coined
“ions,” will separate into their respective components. Meanwhile, molecular compounds, due to having stronger and neutral component atoms, will dissociate an unappreciable amount when placed in water. The more ions that are in a solution, the more electricity that solution will conduct. Due to these inherent differences between compounds, bonds, and disassociation properties, we can further categorize these compounds as either non-electrolytes, weak electrolytes, or strong electrolytes- each of these categorizes reflect to what extent a solution conducts electricity: none, some, and a lot, respectively. Non-electrolytes are usually the molecular compounds, as they do not split into ions and thus do not conduct electricity.
However, the difference between weak electrolytes and strong electrolytes is the difference in the amount of ions that are the product of the placement of compounds into the water- I expect that those solutions that have higher concentration of ions as well as the greater magnitude of charge on these ions will be more conductive. Calculation-wise, we will need to measure the change in conductivity will an increasing amount of volume, which will be recorded using the LoggerPro system. Another calculation would be to write out the disassociation equations for each of the compounds when placed in solution. With this information, we can discern whether or not the conductivity changes when the compound’s volume changes.
Calculations and Discussion:
From our experiment from part A, we are able to categorize the following compounds as such:
As you can tell, the values in the chart above were ordered from least to greatest conductivity.
Using just general statistical clustering, it is apparent that the numbers that revolved around 50 were non-electrolytes, the numbers revolving around 500 were weak electrolytes, and the numbers pushing around 10,000 were strong electrolytes. One thing that stood out to me was the apparent and significant difference between tap and distilled water. Distilled water is basically water without any impurities- distilled water