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a. (20 pts) Determine the unknown specific enthalpies H1 and A2 in units of kJ/kg. To help your calculations, please use the inlet-outlet enthalpy table below and explicitly state your reference states!

(20 pts) Set up and simplify the appropriate form of the energy balance equation. Use this to solve for the work added to the system by the compressor in units of hp.

posted 1 years ago

a. (16 pts) Label the process flow diagram as completely as possible. If you know the amount (or the amount is zero), label it. Otherwise, use a question mark (?) to the right of the variable to indicate that the variable is unknown.

b. (34 pts) Write the complete set of algebraic equations that can be used to solve for these unknowns listed on part a. Do not solve the equations! Remember that your only variables in the below equations should be the unknowns you listed in part a.

posted 1 years ago

(32 pts) Solve for the mass amounts of antibiotic and contaminant leaving the system

Determine the mass fraction of antibiotic in stream 5.

Determine the mass flow rate of oil (mg) needed to recirculate in the system.D/hr):

posted 1 years ago

a. (4 pts) Explain conceptually why increasing air flow rate lowers the adiabatic flame temperature.

b. (8 pts) Determine the theoretical moles of air necessary to completely combust 1 mol/sof acetylene.

c. (28 pts) Determine the unknown inlet and outlet specific enthalpies (and the heat of reaction if using heat of reaction method). To help your calculations, please use the inlet-outlet enthalpy table below and explicitly state your solution method and reference state(s) directly on this sheet!!

d. (12 pts) Write the appropriate form of the energy balance needed to solve for n1 – the unknown molar flow rate of air. Your answer should have n1 on the left hand side of the equation and all remaining knowns and unknowns on the process flow diagram on the right hand side.

posted 1 years ago

Does the value of Ha found in part a) suggest that Ansell has successfully developed a material that will do a “good" jobof protecting your hands from epichlorohydrin? Explain your reasoning briefly.

b) Diffusion coefficients of molecules in most polymers are much higher than in other solids. Hence manipulation of HAlsa promising way to reduce permeation rates in polymeric gloves.

a) A typical value of a diffusion coefficient of a small organic molecule in a polymer is 5 x 10-7 cm2/s. Calculate thepartition coefficient HA of epichlorohydrin in neoprene-natural rubber using this value of DAB.

Their test liquid is epichlorohydrin, a chemical we have used inour lab to crosslink polymers. According to Ansell, gloves made ofa neoprene-natural rubber blend (0.67 mm thick, density of 1.18g/cm3) are rated as "Good" in terms of permeation rate, whichmeans that the steady state permeation rate is no more than 90ug/cm2-min (or 1.6 x 10-8 mol/cm2-s).(E

Ansell Inc. produces chemical-resistant gloves. Their chemicalpermeation test cell is shown in the illustration to the right. Theglove material is used as a thin membrane separating a liquidcompartment from a gas compartment. Nitrogen gas iscontinuously pumped through the gas side of the chamber to keepthe concentration of liquid vapor that has diffused across themembrane close to zero.

Only a qualitatively reasonable sketch is expected (no calculations are necessary), but draw it in terms of molarconcentration for each phase (liquid/solid/gas). Note that the density of the liquid and rubber phases are equal.

posted 1 years ago

a) Find the steady-state molar flux at which water evaporates from the tube. Use both the dilute and concentrated solutions that are appropriate for this problem and compare the results. Identify the reasons for any similarities or differences in the results.

b) What is the molar concentration of the water vapor in the rain gauge 5 cm from the top?

c) Consider the effect of the wind on evaporation and concentration profile under the following conditions:

i) a perfectly calm day

ii) a light breeze

iii) a strong wind

posted 1 years ago

posted 1 years ago

Express the equation in (2) in dimensionless form. List the important dimensionlessgroups and their physical meaning.

Indicate the boundary conditions needed to solve the mass transfer equation for the liquid phase.

Simplify the mass transfer equation to an equation in two-dimensional coordinates.Indicate the reasons for your choice of coordinates.

Write the appropriate mass transfer equation (for the liquid phase) assuming that the liquid velocity profile in the axial direction is uniform (i.e., plug-flow). What are the appropriate boundary conditions?

Write the complete mass transfer equation for oxygen transport in the channel.

posted 1 years ago

A laboratory-scale electrochemical reactor, developed as a rectangular channel flow cell, had length (L) of 30 cm, a cross-sectional width (B) of3.0 cm and a cross-sectional height (s) of 5.0 mm, and was designed so that the flow would be well-developed before it reached the electrodes embedded in the sides of the reactor. Operation of the cell occurred isothermally at293 K, for a liquid electrolyte (of viscosity 1.002 mPa s and density998.2 kg m) for the electrochemical conversion of a reactant. The diffusion coefficient of the reactant in the liquid electrolyte is 2.67 x 10 cm? s at293 K.

(a)Explaining all terms and symbols used, define the following.

What are the units of kinematic viscosity (v)?kinematic viscosity of the liquid electrolyte at 293 K, providing your answer in the units you have previously given.(b)Calculate the

If the equivalent diameter (de) of the laboratory reactor is given byequation (1),(c)

\mathrm{d}_{\mathrm{e}}=4 \times \frac{\text { cross-sectional area }}{\text { cross-sectional perimeter }}

calculate the value of the equivalent diameter of the reactor, andgive its units.

(d)Noting that the Reynolds number (Re) of the reactor is given byequation (2),

\mathrm{Re}=\frac{\mathrm{d}_{e} \mathrm{u}}{\mathrm{v}}

in which u is the mean electrolyte velocity, use the data provided tocalculate, at 293 K, both the Reynolds number and the Schmidtnumber as a function of the volume flow rate. Comment on yourresults.

(e)Use the data provided to calculate the Sherwood number (Sh) as a function of the volume flow rate at 293 K, and then plot Ig(Sh)against Ig(Re) and comment on your plot.

For Re < 2000, the Sherwood number is predicted to be related tothe Reynolds number and the Schmidt number by equation (3)(f)

S h=c R e^{d} S c

where a and b are constants. Use your answers to parts (d) and (e)to calculate the values of a and b. Comment on your findings.

For Re > 2000, the Sherwood number is predicted to be related tothe Reynolds number and the Schmidt number by equation (4)

\mathrm{Sh}=\mathrm{aRe}^{\mathrm{b}} \mathrm{Sc}^{/ / 3}

where c and d are constants. Use your answers to parts (d) and (e)to calculate the values of c and d. Comment on your findings.

posted 1 years ago

Acidic solutions of hypochlorous acid (HCIO) are made when chlorine gas(Cl2) dissolves in water. Reaction of the chlorine with water is considered to be fast.

(a)Write down the reaction between chlorine and water.

If the reaction between chlorine gas and water occurs as a single step, explain why the reaction you have written in part (a) can be considered to be overall pseudo-first order.(b)

(c)Write down the time-dependent reaction-diffusion equation relevant to this problem in extractive reaction.

D is the diffusion coefficient of chlorine in water.

(e)Using your answers to parts (c) and (d) and showing all of your steps, demonstrate that the steady-state concentration profile of chlorine in water is given by equation (5):

\frac{c}{c_{\mathfrak{\theta}}}=\exp \left(-x \sqrt{\frac{k_{-}}{D}}\right)

where:

c is the concentration of chlorine in water,

co is the concentration of chlorine in water at the water/gas interface.

x is the distance in the water from the water/gas interface,

k, is the pseudo-first order rate constant for the reaction of chlorine with water, and

(d)What is meant by the term steady-state?

In experimental studies using a wetted-wall absorption column, themass transfer coefficient for chlorine into water is 200 um s.(f)

i. Explain what is meant by the term wetted-wall absorption column, and describe how they differ from packed tower absorption columns.

ii. What advantages do wetted-wall columns have over packed towers?

iii. Given the diffusion coefficient of chlorine in water is1.25 x 10 cm? s', determine the pseudo-first order rate constant for the reaction between chlorine and water.