30% 3) Calculate the fraction of total 2,3,4,5-tetrachlorophenol (organic acid) that is present in the water phase of a dense fog (air-water volume ratio of about 105) at a pH = 2.0 and a temperature of 278 K. Assume a Δ a w H iof 70 kJ/mol for partitioning of this acid between air and water at 298 K. Assume also that the pKia is independent of temperature. Data for 2,3,4,5-tetrachlorophenol is available in Ap. C.
Hint: Fog is a suspension of tiny liquid water drops in air. In equilibrium, the acid will be distributed between the two phases. You are asked to calculate the ratio between the acid present in the liquid phase and the total amount of acid present in the two phases.
In: Other
The weather report says the temperature is 78.0°F, the barometer is at 29.90 inches Hg, the relative humidity is 67.0%. Estimate the mole fraction of water in the air, the molal humidity, absolute humidity, percentage humidity in the air, and the dew point
a) What is the mole fraction of water in the atmosphere?
b) Determine the molal humidity.(mol H2O)/(mol dry air)
c) Determine the absolute humidity.(g H2O) / (g dry air)
d) Determine the percent humidity.
e) What is the dew point? °F
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The safety rules do not allow the concentration of the toxic solution exceeding 0.1 mg to be released in the environment. In a chemical factory, this toxic chemical solution is used in the process. The solution flows at a constant rate of 4 L/min into a safety tank that initially contains 100 L of pure water. The toxic solution inside the tank is kept well stirred and flows out of the tank at a rate of 3 L/min. The concentration of the toxic solution entering the tank is 0.3 mg/L.
a) Determine the mass of the toxic product in the tank after t minutes.
b) Find when the concentration of the toxic solution in the tank will be 0.1 mg/L.
c) Use Range-Kutta method with increment = Time in (question b) / 4 d) Compare your results by finding the error
In: Other
A gas stream of flow rate 10.0 lbmole/ft2 h
contains
6.0% sulfur dioxide (SO2) by volume in air. It is desired to
reduce the SO2 level in the treated gas to no greater than 0.5% in
a countercurrent packed tower operating at 30°C and 1.0 atm total
system pressure, using water containing no dissolved SO2 as the
absorption solvent. The desired solvent flow rate is 2.0 times the
minimum solvent flow rate. At these flow conditions, the film
mass-transfer coefficients and kxa =250 lbmole/ft3 h, and kya= 15
lbmole/ft3 h, for the liquid and gas films, respectively.
Equilibrium distribution data for SO2 in water at 30°C is provided
in the table below.
Determine the height of packing required to accomplish
the separation or operation at 2.0 times the minimum solvent flow
rate.
In: Other
Steam at 10 bar and 330°C is fed to an adiabatic turbineat a mass flow rateof 5kg/s
. The output stream is saturated steam at 1.1 bar. The inlet steam flows
through a 15 cm diameter pipe and the exit steam discharges through a 20 cm diameter
pipe.
a)
Calculate the velocity of the input and output streams in m/s.
b)
The power generated by the turbine in kW.
In: Other
Steam at 10 bar and 330°C is fed to an adiabatic turbine at a mass flow rate of m = 5 kg/s. The output stream is saturated steam at 1.1 bar. The inlet steam flows
through a 15 cm diameter pipe and the exit steam discharges through a 20 cm diameter pipe.
a) Calculate the velocity of the input and output streams in m/s.
b) The power generated by the turbine in kW
In: Other
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What property of compounds causes separation via gas chromatography? Will compounds of a higher or lower value of this property elute off the column first? How do you tell the number of components and how to calculate their percentage?
In: Other
In: Other
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Let’s consider a portable UV disinfection system to be used with 5-gallon (18.9 L) coolers with a modified lid. The setup will allow water to flow into the top and out a spigot at the bottom. The resulting contactor is effectively a CSTR.
In: Other
The International Space Station uses the electrolysis of water to continuously replenish the oxygen in the station’s atmosphere (the hydrogen formed is vented). The station’s electricity is generated by the four arrays of solar modules, which produce a total of 120 kW. Essential heating/cooling, circulation and steering equipment requires 75 kW. If one of the four modules fails completely, this leaves 15 kW for O2production, which is run at a 2 V potential. How many astronomers can survive on board of the space station if each of them consumes 25 L of O2(g) per hour? Enter your numerical answer (rounded DOWN to the closest whole number, as we cannot have partial astronauts!) in the answer box. Assume 1 atm and 298 K as conditions.
To help you solve this problem, use the following information, suggested steps and hints:
a) Write the balanced half reactions at each electrode and the overall reaction!
b) If the electrolysis is carried out at 2 V potential, how many moles of electrons are produced in 1 s? (Hint: Calculate the Ampere available first using the following relationships: 1 W = 1 J/s; 1 J = 1 V·1 C; 1 C = 1 A·s)
c) Using your results from a) and b), how many moles of O2 can be produced in 1 h?
d) How many moles of O2(g) are required each hour for one astronaut, if s/he consumes 25 L of O2(g) per hour? Assume 1 atm and 298 K.
e) How many astronauts can survive on the O2 produced in c) if each consumes the number of moles calculated in d)?
In: Other
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1. Consider a feed containing benzene, toluene, and cumene with mole fractions of 0.25, 0.5, and 0.25, respectively. The relative volatilities of these components with respect to toluene is 2.25, 1,and 0.21. If the fractional recovery of benzene in the distillate is 0.9 and that of toluene in the bottoms is 0.9, solve for the component flow rates in the bottoms and distillate using the Fenske equation. Assume that the feed flow rate is 100 kmol/hr.
2. Assume that the feed in Problem 1 is saturated liquid. What is the minimum reflux ratio? Use the Underwood equation and toluene as the reference component.
In: Other
A copper pipe of diameter 3.5 cm and wall thickness 4 mm is used in an antibiotic factory to convey hot water a distance of 60 m at a flow rate of 20 L/s. The inlet temperature of the water is 90°C. Due to heat losses to the atmosphere, the outlet water temperature is 84°C. The ambient temperature is 25°C. The inside of the pipe is covered with a layer of fouling with a fouling factor of 7500 W/m2°C.
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