3.S: First Law of Thermodynamics (Summary)
- Page ID
- 84458
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Learning Objectives
After mastering the material covered in this chapter, one will be able to:
- Define the internal energy of a system as a measure of its capacity to do work on its surroundings.
- Define work and heat and relate them to changes in the internal energy of a system.
- Explain the difference between path dependent variables and path independent variables.
- Define enthalpy in terms of internal energy, pressure, and volume.
- Calculate First Law quantities such as \(q\), \(w\), \(\Delta U\) and \(\Delta H\), for an ideal gas undergoing changes in temperature, pressure, and/or volume along isothermal, isobaric, isochoric, or adiabatic pathways.
- Perform calculations using data collected using calorimetry (at either constant pressure or constant volume).
- Write a formation reaction (the reaction for which the standard enthalpy of formation is defined) for any compound.
- Use enthalpies of formation to calculate reaction enthalpies.
- Estimate reaction enthalpies from average bond dissociation enthalpies.
- Define and utilize enthalpies for phase changes such as \(\Delta H_{fus}\), \(\Delta H_{sub}\), and \(\Delta H_{vap}\) to calculate the heat energy transferred in the corresponding phase change processes.
- Define important thermodynamic functions such as ionization energy, electron affinity, bond dissociation energy, and lattice energy. Construct a Born-Haber cycle diagram using these values to describe the formation of an ionic crystalline compound.
Vocabulary and Concepts
- adiabatic
- Bomb calorimetry
- bond dissociation energy
- Born-Haber cycle
- calorimetry
- combustion reactions
- constant pressure heat capacity
- constant volume
- constant volume heat capacity
- electron affinity
- endothermic
- enthalpy
- enthalpy of combustion
- exothermic
- First Law of Thermodynamics
- heat
- heat capacity
- Hess’ Law
- internal energy
- ionization potential
- isothermal
- maximum work
- Reaction enthalpies
- reversible
- reversibly
- specific heat
- standard enthalpy of formation
- standard formation reaction
- state variables
- work
- work of expansion
References
- Balcan, M., Arzik, S., & Altunata, T. (1996). The determination of the heats of combustion and the resonance energies of some substituted naphthalenes. Thermichimica Acta, 278, 49-56.
- Einstein, A. (1979). Autobiographical Notes. A Centennial Edition. Open Court Publishing Company.
- Encyclopedia.com. (2008). James Prescott Joule. Retrieved March 30, 2016, from Complete Dictionary of Scientific Biography: http://www.encyclopedia.com/doc/1G2-2830902225.html
Contributors
Patrick E. Fleming (Department of Chemistry and Biochemistry; California State University, East Bay)