CHEM 111 Lecture Notes - Lecture 41: Automobilclub Von Deutschland, The Last Question, Thermodynamics

• School: BYU
• Department: Chemistry and Biochemistry
• Course: CHEM 111
• Professor: David Dearden

Document Summary

Adiabatic processes q = 0 (no energy transferred except by work) air rising over wasatch w = -pdv = -rtdv/v, du = cvdt = w. 4 steps: isothermal expansion adiabatic expansion isothermal compression adiabatic compression. If an expansion process is irreversible, then |w| < |w(reversible)| irreversible = more energy than reversible reversible = piecewise(?) function in some way. Step 2 (adiabatic) w2 = cvdeltat = cv(tl-th) Step 4 (adiabatic) w4 = cvdeltat = cv(th - tl) w2 = -w4. To maximize the efficiency of a heat engine, you should keep the difference in temperatures of the two reservoirs as large as possible. Any cyclic path can be described as a sum of carnot paths this means irreversible processes can be modeled as a sum of reversible processes for state functions, we can choose any convenient path to calculate change. Kelvin: heat (energy transfer) is proportional to temperature. We can define a temperature scale based on the amount of heat transferred.