Determine the fundamental dimensions of the following quantities.
a. Fuel comsumption with units of kg/Wh
b. Latent heat with units of J/kg
c. Specific weight with units of N/m3
d. Molar heat capacity with units of J/molK
e. Rate of drying with units of kg/m2h
f. Thermal resistance with units of Km2/W
A= Ampere = Unit of current
J = Joule = Unit of energy
K = Kelvin = Unit of temperature
N = Newton = Unit of force
V = Volt = Unit of voltage
W = Watt = Unit of power
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Describe the Blackbody radiation experiment; what did this experiment involve? What problem was encountered (what did classical physics predict versus what was observed)? What was learned or reinterpreted as a result of explaining the experimental results?
Be concise, each part should not take more than 3-4 sentences.
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Which of the following have standard enthalpies of formation values that are not zero: Ar(g), Br2(l), H(g), W(s), Hg(s), Li2(g)? Explain.
When ammonia is formed according to the following equation:
®2 NH3(g)
the standard enthalpy of reaction (as written) is -92.6 kJ/mol. If 25.4 kg of ammonia (NH3) is formed under standard conditions, what is the enthalpy change? Is this reaction exothermic or endothermic? Explain.
Alcoholic fermentation is the process by which carbohydrates decompose into ethanol and carbon dioxide. The reaction is multi-step and complex, but the overall reaction is
®2 C2H5OH(l) + 2 CO2(g)
Given that the standard enthalpies of formation are C6H12O6(s) = -1274.5 kJ/mol, C2H5OH(l) = -277.0 kJ/mol, and CO2(g) = -393.5 kJ/mol, calculate the standard enthalpy for the fermentation reaction.
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Ethane is chlorinated in a continuous reactor: C2H6 + Cl2 --> C2H5Cl + HCl (Rxn 1) Some of the product monochloroethane is further chlorinated in an undesired side reaction: C2H5Cl + Cl2 --> C2H4Cl2 + HCl (Rxn 2) The reactor is designed to yield a 15% conversion of ethane and a selectivity of 15 mol C2H5Cl/mol C2H4Cl2, with a negligible amount of chlorine in the product gas. Calculate the fractional yield of monochloroethane. Use a basis of 100 mol C2H5Cl produced. Report your answer with three significant figures. Note: Reactor feed is ethane and chlorine. Identify the limiting reactant to answer the question.
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Q1- Make a table showing all the similarities and differences
for the following type of corrosion.
1- Galvanic or two metal corrosion.
2- Crevice corrosion.
3- Pitting.
4- Intergranular corrosion.
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You want to supply microorganism in a bioreactor with oxygen; What needs to be considered in terms of mass transfer? What are the challenges what the solutions?
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A large deep lake, which initially had a uniform oxygen concentration of 1 kg/m3 , has its surface concentration suddenly raised and maintained at 9 kg/m3 concentration.
a. Draw a picture of the physical process. Select a coordinate system to describe this diffusion process. Write the general form of the oxygen species continuity equation for this system.
b. Reduce the general differential equation for the mass transfer process for the transfer of oxygen into the lake without the presence of a chemical reaction.
c. Reduce the general differential equation for the mass transfer process for the transfer of oxygen into the lake occurs with the simultaneous consumption of oxygen by a first order biological reaction, ?? = −??0.
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in one full, elaborate paragraph compare and contrast the desalination processes RO AND MSF
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in one pargraph, compare and contrast between the disallination processes, msf and rp
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Bacteria are not limited to organic matter as a source of electrons or energy. Autotrophic denitrification occurs when NO3- is used as an electron acceptor and converted to N2 gas and H2 gas is used a source of electrons.
Below are the two half reactions we will be working with.
2NO3- + 10e- -> N2
2H+ + 2e- -> H2
Which reaction needs to be reversed? Enter the letter A or the letter B
Balance the half reaction for the conversion of nitrate to dinitrogen gas. Input the reaction co-efficient for each component of the half reaction in the blank provided. The co-efficient might be 1 in some cases.
2NO3- + e- + H+ -> N2 + H2O
Balance the half reaction for the conversion of hydrogen gas to hydrogen ions. Questions 12-13 are asking for the reaction co-efficients for each piece of the reaction. The co-efficient might be 1 in some cases.
H2 + -> 2e- + H+
Combine and balance both equations.
NO3- + H+ + H2 -> N2 + H2O
How many electrons were transferred?
What is the redox potential of this reactions in volts? E0cell = ?
Using the Nernst Equation, calculate the Gibbs Free Energy to deduce how many kilojoules are available to do work based on the stoichiometry you determined? ΔG = -nFΔE, where F = 96.48 kJ (mol e-) (Report your answer to 3 decimal places)
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Prepare cyclohexene from cyclohexanol. The cyclohexanol and phosphoric acid (catalyst) are placed in the distillation flask.
a) During the distillation process, why the receiving vessel be sitting in an ice bath? Why need to distil slowly?
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1. Is it reasonable to say that enzymes lower the energy of the transition state for a reaction?
| Yes. Like other catalysts, enzymes speed up reactions by lowering the activation energy, which is the energy of the transition state. |
| No. Since enzymes change pathways of reactions, we cannot say that they lower the energy of the transition state. |
2. Why is the reaction faster when the liver is ground up?
| Grinding speeds up the reaction of formation of catalase in the liver. |
| Grinding increases the solubility of catalase. |
| Grinding increases the surface area. |
| Grinding allows for more catalase to be extracted from the liver to the solution. |
3. Energy profile for conversion of methyl isonitrile (H3CNC) to its isomer acetonitrile (H3CCN). How does the energy needed to overcome the energy barrier compare with the overall change in energy for this reaction?
The magnitude of energy needed to overcome the energy barrier is about the same as the magnitude of the energy change in the reaction.
The magnitude of energy needed to overcome the energy barrier is lower than the magnitude of the energy change in the reaction.
The magnitude of energy needed to overcome the energy barrier is greater than the magnitude of the energy change in the reaction.
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What is the effect of the BOD coefficient (i.e., the biodegradability of the waste in the effluent) on the shape of the DO sag curve?
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The vapor-liquid equilibrium data for heptane – ethylbenzene at 1 atm pressure is given below:
|
x |
0 |
0.10 |
0.20 |
0.40 |
0.50 |
0.60 |
0.70 |
0.90 |
1 |
|
y |
0 |
0.25 |
0.45 |
0.65 |
0.74 |
0.82 |
0.86 |
0.96 |
1 |
A feed mixture containing 40 mol% heptane and 60 mol% ethylbenzene is to be fractionated at 1 atm pressure to produce a distillate containing 95 mol% heptane and a bottom product stream containing 96 mol% ethylbenzene.
Determine the minimum reflux ratio if the feed is a saturated liquid.
Determine the minimum reflux ratio if the feed is a saturated vapor.
Determine the minimum reflux ratio if the feed is an equilibrium mixture of liquid and vapor, with 20% vapor.
Determine the minimum number of theoretical plates using McCabe-Thiele graphical method.
Determine the minimum number of theoretical plates using Fenske equation.
For a saturated liquid feed and a reflux ratio that is 2.25 times the minimum, determine:
-The number of theoretical stages, using McCabe-Thiele graphical method.
-The optimum feed stage location.
-The actual number of stages if the average column efficiency is 58%.
-The top product and bottom product rates if the feed rate is 100 kmol/s.
-The condenser duty.
-The reboiler duty.
|
Latent heat, kJ/kmol |
Heat capacity, kJ/kmol-K |
|
|
Heptane |
35,000 |
220 |
|
Ethylbenzene |
40,000 |
183 |
|
Feed temperature |
30C |
|
Condenser temperature |
95C |
|
Reboiler temperature |
99C |
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Why is mass transfer a major factor in separation processes?
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