True or False
The change in enthalpy of a hypotehtical reversible process and the
change in enthalpy of it's representative actual processes are
equal?
Entropy production is greater for an irreversible process than a
reversible process?
In: Other
In: Other
Discuss why cathode flow channel design is less important for SOFCs than for PEMFCs. Hint: Consider the typical operating temperature of a SOFC and its effect on jL.
In: Other
A double pipe heat exchanger is to be designed to cool 5 gal/min of hot oil from 250°F to 120°F using 10 gal/min of cooling water available at 70°F. The heat exchanger is to consist of sections of 0.75 inch 16 BWG copper tubing inside 1.5 inch 16 BWG tubing; the water flows in the annular space. The shell-side heat transfer coefficient for this system is known to be 737 Btu/hr×ft2×°F.
a) Estimate the required length of the countercurrent exchanger, neglecting the resistance of the tube wall in your calculations.
b) Estimate the required lengthof the exchanger if operated co-currently
The following data are available:
| Oil | Water | |
|
Cp (Btu/lbm°F) |
0.55 | 0.98 |
|
density (lbm/ft3) |
52 | 62.3 |
| viscosity (cP) | 2.2 | 1.0 |
|
k (Btu/hr ft°F) |
0.077 | 0.361 |
Wall thickness for 16 BWG = 0.065 in.
In: Other
What are the major pollutants emitted from the tailpipe of an automobile? Why is each pollutant important? Name one control method or device used on present-day automobiles to control each pollutant?
In: Other
a. What are the two main hazards associated with chemical plants and list three examples of each?
What are Material Safety Data Sheets (MSDSs) and the role of MSDS in Process Design?
In: Other
Buffer capacity is a measure of a buffer solution\'s resistance to changes in pH as strong acid or base is added. Suppose that you have 125 mL of a buffer that is 0.400 M in both propanoic acid (C2H5COOH) and its conjugate base (C2H5COO–). Calculate the maximum volume of 0.290 M HCl that can be added to the buffer before its buffering capacity is lost.
In: Other
1. In oxidation of borneol to camphor why do we add
Sodium bicarbonate?? what role it plays?? what do
we want to get rid of?? what chemical reaction takes
place??
2. In oxidation of borneol to camphor why do we add
Sodium bisulfite?? what role it plays?? what do
we want to get rid of?? what chemical
reaction takes place??
Please answer my questions. 2 questions Thanks.
In: Other
Using the mechanical EOS given in your book, calculate the critical compressibility Zc = PcV c RTc for (a) the van der Waals equation, (b) the Soave equation, and (c) the Peng–Robinson equation. (d) Discuss the relative accuracy of each equation in relation to real fluids by comparing to the critical compressibilities for methane, n-butane, n-octane, methanol and water.
In: Other
In this problem you will be calculating enthalpy changesforN2 . Do not assume constant values of heat capacity. Use a reference state o fT = 25 ̊C and 1 atm pressureto set H = 0 kJ/mol.
a.What is the change in enthalpy thereference state to400 ̊C?
b.What is the change in enthalpy from 800 ̊C to 400 ̊C? In addition, what is the value for enthalpyat 800 ̊C?
c.If the reference state for N2was changed to 100 ̊C, would your answer for part (b) change? If so, what would the change be?
In: Other
Can you please differentiate the Antoine Equation with respect to temperature? ie dPsat/dT
In: Other
1. One of the common fertilizer used to enrich soil with phosphate is
superphosphate, CaH4(PO4)2. Typically, superphosphate is produced by reacting some form of phosphate rock with sulfuric acid. In one preparation, calcium phosphate is reacted with sulfuric acid according to the reaction Ca3(PO4)2 +2H2SO4 CaH4(PO4)2 + 2CaSO4
20,000 kg/day of raw calcium phosphate containing 14wt% inert
impurities is reacted with 15,000 kg/day of 92wt% H2SO4 in water.
95% of the limiting reactant is converted. The molecular weight of
Ca3(PO4)2 and H2SO4 are 310 and 98, respectively
a) What is the limiting reactant? Show your work
b) What are the flow rates (in kmol/day) of the exiting species
In: Other
| Fraction dry weight | |
| N | 0.12 |
| P | 0.02 |
| S | 0.01 |
| K | 0.01 |
| Na | 0.01 |
| Ca | 0.005 |
| Mg | 0.005 |
| Cl | 0.005 |
| Fe | 0.002 |
Prepare a recipe for an inorganic medium to be used in a laboratory CSTR to grow 500 mg VSS/d of bacteria biomass, assuming that the composition of the biomass is as listed below. Determine the concentration of essential inorganic compounds required for a feed rate of 1 L/d. Assume that phosphorus is added as KH2PO4, sulfur as Na2SO4, nitrogen as NH4Cl, and other cations associated with chloride. Note: assume that 90% of the biomass (sludge) is organic, i.e., VSS = 0.90·TSS
In: Other
In: Other
1.) Saturated liquid water flowing at 3kg/s is initialy at 30 bar.
a.) this steam is throttled through a valve to 9 bar. What is the vapor fraction of the steam after the valve?
b.) afterwards, 6.0 MW is added to the steam. What is the final temperature of the steam?
What is the entropy change for this heating, in kW/K?
In: Other