An insulated tank, fitted with a freely moving frictionless piston, has an initial volume of 1 m3 and contains 20 kg of refrigerant 134a at 200 kPa. A stirrer with a rotation rate of 300 rpm and a torque of 15 J/rotation is included in the tank. Find the time required for the refrigerant to evaporate completely.

Ans= [73.36 minutes]

Quickly estimate the change in enthalpy (J/mol) to go from CO2 at 223K and 10 bar to 298K and 90 bar and sketch a graph.

Quickly estimate the change in internal energy (J/mol) to go from CO2 at 273K and 10 bar to 340K and 105 bar.

Consider a hypothetical metal that has a density of 8.40 g/cm3, an atomic weight of 108.6 g/mol, and an atomic radius of 0.136 nm. Compute the atomic packing factor if the unit cell has tetragonal symmetry; values for the A and C lattice parameters are 0.494 and 0.352, respectively.

For a distillation coloumn sperperating a non-ideal liquid mixture using ASPEN PLUS, which thermodynamic model should I use (NRTL, UNIQUAC, UNIFAC, etc) and why should I use this specific model and not the others (justification required)

Mercury has a surface tension coefficient σ = 0.487N/m. A Mercury barometer has a cylindrical tube that is 5mm in diameter.

a) By how many mm will the Mercury level change due to capillary forces? Follow the procedures and assumptions of the example in the notes.

b) Air pressure at sea level typically causes Mercury level to rise by 760mm. What is the percent error due to capillary force?

c) Repeat parts a and b for a tube that is 0.1mm in diameter.

d) Repeat parts a and b for a tube that is 20mm in diameter.

Oxidative dehydrogenation of ethane is the conversion of ethane with oxygen to yield ethylene and water.In addition to oxidative dehydrogenation, ethane/oxygen mixtures can also undergo partial oxidation, i.e. the formation of synthesis gas (CO and H2), as well as total oxidation, i.e. complete combustion of ethane towards CO2 and water.Hydrogen is of great interest as a feed for fuel cells. However, in order to use the hydrogen content of the syngas produced via partial oxidation of ethane, one would need to remove virtually all the CO from the mixture since CO is a strong poison for most fuel cells. This could be done through addition of steam in order to convert the CO via the so-called ‘water gas shift’ reaction (WGS: CO + H2O = CO2 + H2). Assuming a feed flow of 100 L/min of a feed mixture 75vol% air and 25vol% ethane, and furthermore assuming that the partial oxidation reaction goes to completion, how much steam needs to be added in order to completely convert the CO? (Assume stoichiometric conversion via WGS.) What is the composition of the effluent stream (in molar fractions)?

A gas is leaking from a rigid tank into the air. Which of the following represents the BEST energy balance?

Determine, using the procedures outlined by RCRA, if each of the following is a hazardous waste. State the reason why it is or is not a hazardous waste. If it is a hazardous waste, list the RCRA waste category number. Assume that the industry producing the waste is a RCRA hazardous waste generator.

a.Soil on the industrial property contaminated by the spill of a 5-gallon (18.9 L) container of endrin.

b.A drum of off-specification ethyl acetate that is to be disposed of.

c.Cement kiln waste.

d.Sawdust in a warehouse contaminated by a spill of pentachlorobenzene.

e.Distillation bottoms from aniline production.

f.Sludge from the treatment of water from the chemical conversion coating of aluminum.

g.1000 Kg of commercial beryllium (pure) that are to be discarded because the company that purchased this chemical originally doesn’t need it anymore.

h.An aqueous industrial waste stream from a plastic manufacturing plant that is discharged to a river.

i.A drum of sulfuric acid at pH 0.50.

j.A drum of waste 20% perchloroethylene.

k.Spent cyanide plating bath solutions from electroplating operations. .

l.Wastewater treatment sludge from the production of zinc yellow pigments. .

A solution of ethanol is pumped to a vessel 25 m above a reference level through a 25-mm-inside-diameter steel pipe at a rate of 10 (m^3)/h. The length of pipe is 30 m and contains two elbows with friction equivalent to 20 diameters each. Compute the power requirements of the pump. Solution properties include density of 975 kg/(m^3) and viscosity of 4*10^-4 Pa s. Hint: frictional loss due to elbow is equivalent to having additional length of pipe that is equal to 20 times the diameter of pipe. So you just calculate that additional length and add it to 30 m length of pipe.

a) There should be a difference in your results between the solubilities of biphenyl and benzophenone in methyl alcohol. (Biphenyl and methyl alcohol are partially soluble..... and benzophenone and methyl alcohol are soluble). Using chemical structures, clearly illustrate the intermolecular force responsible for this difference in solubility for the 2 compounds.

b) explain the solublity behavior of the indicated alcohol in water and hexanes. In each case, be sure to indicate the relevant intermolecular forces between solute/solute, solvent/solvent, and solute/solvent. Case 1: methyl alcohol. Case 2: 1-butanol. Case 3: 1-octanol. (Information needed: methyl alcohol is soluble in water and partially soluble in hexane. 1-butanol and 1-octanol both are insoluble in water and both soluble in hexane.

c) give a brief explanation that explains the solublity trend observed for benzoic acid. you must explicity descrive the intermolecular forces involved. (information: benzoic acid is insoluble in water. soluble in 1.0 NaOH but when you add 6.0 M HCl to the same tube, it becomes insoluble. benzoic acid is insoluble in 1.0 M HCl)

d) give a brief explanation that explains the solublity trend observed for benzoic ethyl-4-aminobenzoate. you must explicity descrive the intermolecular forces involved. (information: is ethyl-4-aminobenzoate insoluble in water. isoluble in 1.0 NaOH. soluble in 1.0 M HCl but when you add 6.0 M NaOH to the same tube, it becomes insoluble)

Consider now a turbine that operates with steam with T1 = 450◦C and P1= 8.0 MPa and P2 = 30 kPa. The efficiency is 80% and the mass flow rate is 80 kg/s. You may assume the velocities are zero. You may also assume q=0.

What is the exhaust temperature and quality (if saturated) for 100% efficiency?

A solar collector installed on the roof of a SoCal home is used to heat water flowing through ducts attached at the back of the collector. The absorbing surface has an area of 2 m2 with an emissivity of 0.9. The surface temperature of the absorber is 35 °C, and solar radiation is incident on the absorber at 450 W/m2. Temperature of surrounding air is 22 °C. Heat transfer coefficient at the absorber surface is 5 W/m2·K. If water is pumped through the ducts at 5 g/s, determine the temperature rise of the water. Water has a specific heat capacity of 4.2 kJ/kg·K. How does the temperature rise change when conditions become breezy forcing the heat transfer coefficient to increase to 25 W/m2.K?

The total capital investment for a conventional chemical plant is $1,500,000, and the

plant produces 3 million kg of product annually. The selling price of the product is

$0.82/kg. Working capital amounts to 15 percent of the total capital investment. The

investment is from company funds, and no interest is charged. Raw-materials costs

for the product are $0.09/kg, labor $0.08/kg, utilities $0.05/kg, and packaging

$0.008/kg. Distribution costs are 5 percent of the total product cost. Estimate the

following:

(a) Manufacturing cost per kilogram of product.

(b) Total product cost per year.

(c) Profit per kilogram of product before taxes.

(d) Profit per kilogram of product after taxes (use current rate)

The fresh feed to an ammonia production process contains N2 and H2 in stoichiometric proportion, along with an inert gas (I). The feed is combined with a recycle stream containing the same three species, and the combined stream is fed to a reactor in which a low single-pass conversion of N2 is achieved. The reactor effluent flows to a condenser. A liquid stream containing essentially all of the NH3 formed in the reactor and a gas stream containing all the inerts and the unreacted N2 and H2 leave the condenser. The gas stream is split into two fractions with the same composition: one is removed from the process as a purge stream, and the other is the recycle stream combined with the fresh feed. In every stream containing N2 and H2, the two species are in stoichiometric proportion. The mole fraction of inerts in the fresh feed is 0.01, the single-pass conversion of N2 (and H2) in the reactor is 0.2, and the fraction of gas leaving the condenser that is purged (mol purged/mol total) is 0.1. Taking a 1 mole fresh feed basis, find the composition of each stream in the process and the overall conversion of N2.