1) 10000 lb/h of a 40.00% NaoH solution is crystallized through a combined evaporator-crystallizer process. The feed enters an evaporator which concentrates it to 50.00% NaOH. The concentrated solution then enters the crystallizer with a built in filter. The crystal product is 95% NaOH crystals with the remaining 5% as adhering mother liquor solution. The mother liquor, containing 45.00% NaOH, is mixed back to the feed before entering the evaporator. Determine the recycle flow rate.
2) Resolve the problem, now considering if the mother liquor is not recycled, but the entire process still generates the same amount of product (crystals) as the original problem. Retain all concentrations given. Determine the amount of feed needed if the recycle stream was removed. Compare the recovery ratio (lb NaOH recovered as crystals/lb NaOH in feed) for the two cases to see the importance of the recycle stream.
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Questions:
The densities of ice and water at 0 °C are 0.9168 and 0.9998 g cm–3,respectively. If ∆H for the fusion process at atmospheric pressure is 6.025 kJmol–1,
What is ∆U?
How much work is done on the system?
For each of the following processes, state which of the quantities ∆U, ∆H, and ∆S are equal to zero. Explain with logical reasoning.
Isothermal reversible expansion of an ideal gas.
Adiabatic expansion of an ideal gas through a throttling valve.
Vaporization of liquid water at 80 °C and 1 bar pressure.
Reaction between H2SO4 and NaOH in dilute aqueous solution at constant temperature and pressure.
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A 75 mL sample of water was placed in a 300 mL BOD bottle, and dilution water was added to fill the bottle. The initial DO concentration was 8.28 mg/L. The DO reading after 5 days was 4.56 mg/L and after 8 days was 3.59 mg/L.
Determine the reaction constant (k) - a trial-and-error solution needed Determine BODu
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Monochlorobenzene (C6H5Cl) is produced commercially by the direct catalytic chlorination of benzene (C6H6). In the process, dichlorobenzene(C6H4Cl2) is generated as a coproduct.
?6?6 + ??2 → ?6?5?? + ??? ?6?5?? + ??2 → ?6?4??2 + ???
Given that the molar ratio of benzene to chlorine in the feed is 5 to 1; and the feed contains only benzene and chlorine. Chlorine is the limiting reactant and completely consumed in the reaction. The fractional yield of C6H5Cl is 0.875
. a. Take a basis of 100 mol C6H5Cl produced, draw and label a flowchart. Do a degree of freedom analysis based on atomic species balances.
b. Calculate the amount of feed and product components of the reactor using the atomic species balances. Present the calculated values in a table to prove that the total mass to the reactor is equal to the total mass out from the reactor (mass conservation).
c. Calculate the percentage conversion of C6H6. The value that you have calculated should be low. Why do you think the reactor would be designed for low conversion? What additional processing steps are likely to take place downstream of the reactor in order to improve the conversion?
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In an attempt to reduce the extraordinarily long
travel times for voyaging to distant stars, some people have
suggested traveling at close to the speed of light. Suppose you
wish to visit the red giant star Betelgeuse, which is 430 ly l y
away, and that you want your 20,000 kg k g rocket to move so fast
that you age only 38 years during the round trip.
How fast must the rocket travel relative to
earth?
How much energy is needed to accelerate the rocket to
this speed?
How many times larger is this energy than the total
energy used by the United States in the year 2000, which was
roughly 1.0×1020J1.0×1020J?
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111 m3/min of hydrogen measured at normal conditions and nitrogen at a 300% excess enter an isobaric reactor. The inlet gases at 490°C are reacted in the presence of a catalyst to synthesize ammonia. The process has an efficiency of 33%. The exhaust gases are cooled to -40°C to condense the ammonia. Assume that the Cp of the gas phase species can be used in the temperature range, and that Cp NH3 (l) = 0.071938 kJ/mol K. Calculate the overall heat flow of the system in kW.
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In 2000 words
: Discus how the fourth industrial revolution could impact on improving electricity sector in South Africa
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Match the rock families with the processes that form them.
Group of answer choices
Cooling of magma.
[ Choose ] Igneous Rock Metamorphic Rock Sedimentary Rock
Layers of sediment lithify
[ Choose ] Igneous Rock Metamorphic Rock Sedimentary Rock
High temperature, high pressure, and hydrothermal fluids
[ Choose ] Igneous Rock Metamorphic Rock Sedimentary Rock
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AgOH (s) ↔ Ag+ + OH-
If the pH of a specific wastewater is initially 6.5 and after treatment is 10.0, what is the maximum concentration of soluble Ag+ in mg/L a) prior and b) after treatment? c) Is pH 13 enough to reduce silver concentrations to Secondary MCL (maximum contaminant level) of 0.1 mg/L?
Data:
1) Atomic weight: Ag=107.87 g/mole; O=16.00 g/mole; H=1.01 g/mole;
2) Assume that any other compounds or metals in this wastewater do not influence this solubility reaction.
3) The temperature of the wastewater is 25 ºC.
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How would your ecological footprint be different if you lived in a less industrialized country?
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Q) Which of the following statements is not correct?
The Eastern hemisphere is defined by longitude
The Prime Meridian is 0 degrees of latitude
The international date line is in the middle of the Pacific Ocean
Lines of latitude are parallel
The Arctic circle is outside of the circle of illumination on December 22nd
Q) At the equator the daylength on June 1 is...
8 hours
14 hours
12 hours
24 hours
0 hours
Q) What portion of the atmosphere does the biosphere primarily interact with?
ozonosphere
lithosphere
troposphere
Heterosphere
Q) Which of the following is not a way in which we define the atmosphere in geography?
function
temperature
height
Composition
Q) Mountain-valley breezes are caused by
valley air ascending the mountain slopes at night
warmer air descending mountain slopes during the day
gravity drainage
warm air rising upslope during the day and cooler air descending the slopes at night
Q) Which of the following is true of objects and wind moving over a distance on Earth's surface?
They are affected only by the pressure gradient and the friction force
They are apparently deflected clockwise from a straight path in the Northern hemisphere.
They are always deflected from a straight path to the west in the southern hemisphere
They are always deflected clockwise by the friction force
Q) The largest portion of fresh water today is located in
ice caps and glaciers
clouds
the major rivers and lakes of the world
groundwater resources
Q) The property that makes water 'wet' and is the cause of capillary action is:
molecular hold
hydrogen bonding
covalent bonding
atomic friction
Q) The Pacific Northwest region of the US is a moist environment because of
the effect of maritime air masses
all of the above
the predominant direction the winds blow at that latitude (45 to 50 degrees north)
the presence of mountains
Q) Which of the following lists the correct, generalized sequence of Koppen climates from the equator to the poles?
H --> B --> C --> D --> A
A --> B --> C --> D --> E
H --> D --> C --> B --> A
E --> D --> C --> B --> A
Q) The gas that is thought to be responsible for more than half of the anthropogenic warming of the atmosphere is
water vapor
carbon dioxide
methane
CFC's
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1a. A ternary mixture contains 20 mol % A , 40mol % B, and 40 mol % C. At a pressure of 80 atm and a temperature of 75?C the fugacity coefficient of components A ,B and C in this mixture are 0.4, 0.6 and 0.8 respectively. What is the fugacity of the mixture?
Explain the basis of the equation you use in (a).
1b. For the system ethyl ethanoate (1) /n -heptane (2) at 450K , assuming the validity of the modified raoult’s law
Given the following data;
Iny1 = 0.95X22 ; Iny2 = 0.95X12 P1sat 80.0 kpa ; P2sat = 41.0 kpa.
2. a. A binary mixture consists of acetonitrile (1) and nitromethane (2) which conform closely to raoult’s law. Vapor pressures for the pure species are given by the following antoine equations;
In(P1sat ,Kpa) = 2945.5t?C+224..0
In(P2sat ,Kpa) = 2972.6t?C+209.0
Determine the bubble point pressure and vapor composition for a mixture of composition X1 = 0.6 at a temperature of 65?C.
b. State the criteria for equilibrium for vapor -liquid composition.
c. Given the excess Gibb’s free energy of a solution as :
GEX1RT = B( 1-X1) find the activity coefficient expression arising out of the binary solution model .
At 30?C and 1 atm, the volumetric data for liquid mixtures of benzene (b) and
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provide 5 ways/methods and explain them on how global warming can be reduced in the future?
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Describe in 2-3 sentences about fundalmental analysis
and techniqual analysis of forecasting
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