Term
| 1st Law of Thermodynamics |
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Definition
Energy is a conserved quantity in all forms.
∆U = Q + W |
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Term
| 2nd Law of Thermodynamics |
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Definition
General: real processes can only increase the total entropy of the universe.
Clausius: heat cannot spontaneously flow from a lower to higher temperature.
Kelvin: it is impossible to convert heat completely into work.
W/Qh = (Qh-Qc)/Qh |
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Term
Ideal Batch Reactor
+ Assumptions |
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Definition
Closed system.
Perfect mixing--no concentration or reaction rate variations in space.
dN/dt = r*V |
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Term
Ideal CSTR Reactor
+ Assumptions |
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Definition
Steady state system.
Perfect mixing--no concentration, reaction rate, or temperature variations in space.
V = (F0-F)/r |
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Term
Ideal Plug Flow Reactor
+ Assumptions |
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Definition
Steady state system.
No radial variations, but concentration and reaction rate vary with axial distance.
dF/dV = r |
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Term
| Energy/Wavelength of Ultraviolet Photons |
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Definition
Wavelength: 10 to 400 nm
Energy: 124 to 3 eV
3% of Sunlight (32 W/1004 W) |
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Term
| Energy/Wavelength of Visible Photons |
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Definition
Wavelength: 400 to 700 nm
Energy: 3 to 1.7 eV
44% of Sunlight (445 W/1004 W) |
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Term
| Energy/Wavelength of Infrared Photons |
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Definition
Wavelength: 700 nm to 1000 um
Energy: 1.7 to 1.2 meV
53% of Sunlight (527 W/1004 W) |
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Term
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Definition
Equal balance between any powers, influences, etc.; equality of effect.
The condition existing when a chemical reaction and its reverse reaction proceed at equal rates. |
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Term
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Definition
| Moles of a species generated per volume per unit time. |
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Term
| General Reactor Mass Balance |
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Definition
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Term
| General Reactor Energy Balance |
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Definition
| -d(uT)/dV + [Hrxn/(ρCp)]r + g = dT/dt |
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Term
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Definition
| A stable condition that does not change over time or in which change in one direction is continually balanced by change in another. |
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Term
| 3 Basic Ideal Reactor Types |
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Definition
| Batch Reactor, Continuously Stirred Tank (Vat, Backmix) Reactor, and Tubular (Plug Flow, Laminar Flow, Packed Bed) Reactor. |
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Term
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Definition
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Term
| Fermentation Reaction Rate |
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Definition
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Term
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Definition
Step 1: incandescent coke (C) + H20 (steam) yield CO and H2 (endothermic)
Step 2+3: C + 02 yield CO2 (exothermic) providing energy for CO2 + C to yield 2CO.
Net exothermic reaction:
C + H2O -> CO + H2 |
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Term
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Definition
CO + H2 are reacted in the presence of an Fe or Co catalyst (exothermic).
Methane, synthetic gasoline, waxes, and alcohols are made. Water or carbon dioxide is a byproduct. |
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Term
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Definition
Industrial steam cracking: heating gases and light hydrocarbons to 750-950 C to induce free radical mechanisms.
Lab scale: heat ethanol with sulfuric acid. |
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Term
| Fuel Cell Electrode Reactions |
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Definition
Anode: 2(H2) -> 4(H+) + 4(e-)
Cathode: O2 + 4(H+) + 4(e-) -> 2(H2O)
Net: 2H2 + O2 -> H2O |
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Term
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Definition
Oxidation is the loss of electrons by one species to another, typically at the anode of a voltaic cell.
Reduction is the gain of electrons by one species from another, typically at the cathode of a voltaic cell. |
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Term
| Collision Theory of Reactions |
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Definition
Implies that the reaction rate is proportional to the collision frequency, energy, and orientation. Theoretical explanation for the Arrhenius equation prefactor.
For bimolecular reactions:
k(t)=Zρe^(-Ea/(KT))
Z=N²σ(8kT/πμ)^(1/2) |
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Term
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Definition
1. Rates of the reactions are studied by studying activated complexes which lie at the col (saddle point) of a potential energy surface. The details of how the complexes are formed are not important.
2. The activated complexes are in a special equilibrium (quasi-equilibrium) with the reactant molecules.
3. The activated complexes can convert into products which allows kinetic theory to calculate the rate of this conversion. |
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