University of North Texas 
Chemistry Institute
Faraday's Candle: A Lesson In Observation
Concept Statements:
- Observations are used to formulate new questions, hypotheses, and theories regarding the phenomenon being observed.
- Much of Michael Faraday's work has resulted in development of materials and technologies that we use today such as electric motors, cathode ray tubes, and catalytic converters. His discovery of various organic compounds have led to further syntheses of other organic compounds.
Discovering Solubility Rules
Concept Statements:
- Solubility is the temperature-dependent quantity of a substance that will dissolve in a given quantity of solvent.
- Solubility is an intrinsic property of a substance.
- The level of solubility is determined by the nature of the solute and the nature of the solvent.
- The compounds that are always soluble in water are sodium compounds, potassium compounds, ammonium compounds, and nitrate compounds.
- Precipitation reactions, a form of double replacement reactions, occur because one product is insoluble in an aqueous system.
Thermochemical Equations
Concept Statements:
- Chemical reactions involve a transfer of energy.
- Chemical reactions can be classified as either endothermic or exothermic.
- A sufficient quantity of activation energy is required for bonds to break and form new bonds.
- The amount of heat either absorbed or released by a reaction in a calorimetry experiment is equal to the amount of enthalpy absorbed or released by the reaction.
- Energy is an important theme that is applied throughout the real world (e.g., hydrocarbon fuels and energy production in biological systems).