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EB 2240 Exam II
Exam II Notecards- Bio[chemical] Energetics
Question | Answer |
---|---|
What is the Zeroth law of thermodynamics? | if two systems are in thermal equilibrium with a third system, they are also in thermal equilbirum with each other |
What is the First Law of thermodynamics? | Conservation of energy: energy can neither be created nor destroyed. It may change from one form to another, but the energy in a closed system remains constant |
What is the Second Law of thermodynamics? | Law of increased entropy: the products will always have less PE than the reactants |
What is the third law of thermodynamics? | the entropy of a perfect crystal at absolute zero is 0. And implies that it is impossible to cool a system a exactly absolute zero |
Describe a perpetual motion machine of the first kind | Produces work without the input of energy |
Why is a perpetual motion machine of the first kind impossible? | 1st law--there is a finite amount of energy in the universe (cannot be created from nothing) |
Describe a Perpetual Motion Machine of the 2nd kind? | Extracts heat from a source and then converts this heat completely into other forms of energy. (only one heat reservoir is involved which is being spontaneously cooled w/o transfer of heat) |
Why is the perpetual motion machine of the 2nd kind impossible? | Second law of thermodynamics states that the entropy of an isolated system never decreases -- isolated systems are constantly moving towards the maximum state of entropy |
Describe a perpetual motion machine of the 3rd kind | One that completely eliminates friction and other dissipative forces to maintain motion FOREVEEERRRR (due to its mass inertia) |
which law of therm. explains that the total amount of energy and matter in the Universe remains constant, merely changing from one form to another | first law |
Which law of therm. states that in all energy exchanges, if no energy enters or leaves the system, the PE of the state will always be less than that of the initial state (ENTROPY) | second law |
T or F: an important goal of thermodynamics is to predict if a rxn or process is spontaneous or not | True |
Define Gibbs Free Energy/Gibbs Function | Usuable energy available to do work |
What are standard conditions? | 25C (298.15K), 1atm, ph7 |
What are the favorable values of enthalpy and entropy? | Enthalpy (-dH) and Entropy (+dS) |
What are the unfavorable values of enthalpy and entropy? | Enthalpy (+dH) and Entropy (-dS) |
What is the value of 4.184 KJ/mol in kcal/mol | 1 kcal/mol |
Are entropy and enthalpy state functions or process functions? | State Funcitons! |
Describe state functions: | Path independent (describe the state irrespective of how the system arrived in that state) |