Hess Law

Words: 539
Pages: 3

Chem 1 Lab Exam # 3 Study Guide
Hess’ Law:
• What is Hess’ Law?
• Know the three reactions.
• Calculate the heat of the reaction per mole of reactants from each reaction.
• Memorize the equation used.
• Don’t memorize the dCp constant.
• Do problems from Hess’s law lab extension

Making Alum from Aluminum
• Know the procedure for the lab.
• Be able to calculate the theoretical amount of alum formed given a certain amount of Al to start.
• Know the mole ratio for the reaction. Don’t memorize the molar mass of alum.
• How was aluminum changed throughout the whole reaction process? What compounds were formed?
• How is the solubility of alum in water affected by temperature?
• Why was methanol used to dry the crystals?
• Be able to calculate percent
…show more content…
• Why do atoms produce an emission spectrum instead of producing a continuous rainbow-like spectrum?
• Are any two emission spectra the same for different elements?
• The emission spectrum of hydrogen is a lot simpler than the emission spectrum of other elements, why?
• Why was it necessary to “calibrate” your spectroscope box? And, how did we do that?
Know how to…
• Determine wavelength values by looking at a calibration curve.
• Convert wavelength values in nanometers to corresponding photon energy in kJ/mole.
• Calculate the value of the Rydberg constant, in kJ/mol, for a wavelength. The Rydberg equation would be given.

Writing Lewis Dot Structure
Know how to…
• Draw lewis dot structures, expanding octets when necessary to minimize formal charge.
• Predict the number of resonance forms present for a given dot structure.
• Predict the best skeletal structure or the most dominant resonance form by using formal charges.

Molar Ratio-Redox Titration
• Know the answers to any of the “further questions” at the end of this lab.
• Understand why we were able to say moles Fe2+ titrated was the same as moles Fe3+ that reacted with