Questions
Two representative pollutants are radon (222Rn) and benzene. Parameters needed for the estimation are listed in...

Two representative pollutants are radon (222Rn) and benzene. Parameters needed for the estimation are listed in the table below. Answer the following questions.

(a) Estimate the steady-state radioactivity in the station in Bq m-3.

(b) Estimate the steady-state concentration of benzene both in mg m-3 and in ppbv. Molecular weight of benzene is 78 g mol-1. Assume 298 K and 1 atm (= 101,325 Pa).

(c) Although regulatory limit of indoor benzene concentration is 30 mg m-3 in Korea, researchers argue that it should be as low as 1.3 mg m-3 considering carcinogenic risk of benzene. Can you lower the benzene concentration as low as for protection of citizens’ health? Suggest potential options to lower benzene concentration in the station.

Parameter

Symbol

Value with units

Volume of indoor air

V

30,000 m3

Air-exchange rate

ke

2.0 h-1

First-order decay constant of 222Rn

kd, Rn

0.00754 h-1

Rate of production of radioactivity of 222Rn inside the station

Ri, Rn

10 Bq m-3 h-1

Outside background radioactivity

Ao

4.0 Bq m-3

Rate of production of benzene inside the station

Ri, benz

3.0 mg m-3 h-1

Outside background concentration of benzene

Co, benz

1.5 mg m-3

Half-life of benzene in the station

t1/2, benz

8.0 h

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Identify one SMART financial goal. What do you think is the best way to invest to meet that financial goal?

Identify one SMART financial goal. What do you think is the best way to invest to meet that financial goal? Explain why.

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All statements are thermodynamically correct, EXCEPT: a) The Gibbs free energy variation for vaporization under T...

All statements are thermodynamically correct, EXCEPT:

a) The Gibbs free energy variation for vaporization under T and P constants is always positive
b) If a saturated liquid undergoes reversible adiabatic expansion to a lower pressure, then some of the liquid will vaporize
c) The heat capacity at constant pressure of a monocomponent system consisting of liquid and vapor in equilibrium is infinite
d) The heat capacity at constant volume of a monocomponent system consisting of liquid and vapor in equilibrium is infinite

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Please provide me a correct and clear answer for this question. Physical and chemical properties of...

Please provide me a correct and clear answer for this question.
Physical and chemical properties of propylene glycol methyl ether
Please attach the references
Thanks in advance

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we discussed two-film theory and the use of the overall mass transfer coefficients that will be...

we discussed two-film theory and the use of the overall mass transfer coefficients that will be one of our foundational components in solving practical mass transfer problems over the course of the semester. In your own words, explain what two-film theory is and how it simplifies real mass transfer across an interface? How does the overall mass transfer coefficient develop from two-film theory? Finally, what is the difference between the overall mass transfer coefficients based on the gas and liquid phase and why might we use one over the other?

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Calculate the freezing point of a solution containing 104 g FeCl3 in 153 g water. Calculate...

Calculate the freezing point of a solution containing 104 g FeCl3 in 153 g water.

Calculate the boiling point of a solution above.

Calculate the freezing point of a solution containing 55.2 % KCl by mass (in water).

Calculate the freezing point of a solution containing 3.34 m MgF2.

Calculate the boiling point of a solution above

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A 10 m3 mixture solution contains molecules A, B and C in water at ambient temperature....

A 10 m3 mixture solution contains molecules A, B and C in water at ambient temperature.

Calculate:

(a) Each species mass concentration.

(b) Their molar concentration.

(c) Total mass concentration and molar concentration.

(d) Mass and mole fraction.

given:

Vmix= 10 m3

mA= 0.3 kg , mB= 0.5 kg , mC= 0.4 kg , mH2O= 9.8 kg

MWA= 50 , MWB= 250 , MWC= 10 , MWH2O= 18

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Is the value of Cd a function of the fluid which is flowing through the meter?...

Is the value of Cd a function of the fluid which is flowing through the meter? What other effect does Cd accommodate in the case of viscous fluids (in addition to viscous or friction losses)?

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Find the pH of each mixture of acids. a) 8.0×10−2 M in HNO3 and 0.175 M...

Find the pH of each mixture of acids.

a) 8.0×10−2 M in HNO3 and 0.175 M in HC7H5O2

b) 1.5×10−2 M in HBr and 2.0×10−2 M in HClO4

c) 9.0×10−2 M in HF and 0.230 M in HC6H5O

d)0.100 M in formic acid and 4.5×10−2 M in hypochlorous acid

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Please provide me a correct and clear answer for these questions. 1. explain the growth curve...

Please provide me a correct and clear answer for these questions.
1. explain the growth curve of bacteria e coli?
2. Draw, label, explain function of each part in cstr bioreactor?
3. types of impeller with picture ?
Thanks in advance

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A mixture of n-heptane (A) and ethyl benzene (B) is to be separated in a distillation...

A mixture of n-heptane (A) and ethyl benzene (B) is to be separated in a distillation column operated at 1 atm. The feed flowrate is 300 mol/h and contains 40 mol% n-heptane. 60 % of the feed is liquid. It is required to obtain an overhead product containing 96 mol% n-heptane and a bottom product containing 5 mol% n-heptane. Find the following:

a) The distillate and bottom flowrates

b) The minimum reflux ratio

c) The minimum number of stages

d) The number of stages at a reflux ratio of 1.5Rmin

The following is the equilibrium data for n-heptane/ethyl benzene at 1 atm.

xA

yA

0.000

0.000

0.080

0.230

0.250

0.514

0.485

0.730

0.790

0.904

1.000

1.000

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How do you mathematically derive the "2nd Law of Thermodynamics"?

How do you mathematically derive the "2nd Law of Thermodynamics"?

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in general when would one purify a material prior to feeding it to a process unit?...

in general when would one purify a material prior to feeding it to a process unit? give at least one example for each case you state

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A pulp mill utilizing the saw dust from nearby lumber mills to produce a market pulp...

A pulp mill utilizing the saw dust from nearby lumber mills to produce a market pulp for paper production. A recent development had the company thinking of increasing the pulp production by 50% for entering the nonwoven market. A close examination at the pulp mill has the engineers to conclude that the digesters were the bottleneck. Currently, the woodchips were steamed, mixed with a pulping liquor and underwent delignification at 150°C for 3 hours. For each load of woodchips, a minimum of 2 hours is needed for loading, heating the digester up, explosive decompression unloading, and cleaning up the digester for the next load. Your task is to find a way to ease the bottleneck quickly at a low cost. State your assumptions clearly and your solution to the problem as stated.

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Q1. A hydroelectric power plant uses the reaction of ethylene (?2?4) with oxygen to generate vapour....

Q1. A hydroelectric power plant uses the reaction of ethylene (?2?4) with oxygen to generate vapour. The products of this reaction are carbon dioxide and water. Additionally, the reaction produces −1323.16?? per mol of ethylene consumed. a) How much ethylene is required by the power plant if 8500 kg of steam at 120 °C is produced in an hour? (assume 100% yield) (12.5 marks) b) Recalculate your answer for a 75 % yield. (12.5 marks) Assumptions. The heat capacities of water are C?? = 4.19 kJ⁄kg°C, ??? = 1.996 ??⁄??°C, the heat of ?? vaporization for water is ∆h? = 2256.9 ⁄??, and the power plant takes water from a source at 15 °C.

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