Past boards Flashcards
Histogram Definition
a graph used to represent the frequency distribution of a few data points of one variable. Histograms often classify data into various “bins” or “range groups” and count how many data points belong to each of those bins.
Pioneered the use of zeolites in water softening
Robert Gans
Earth Wax
Ozocerite
Kailan hindi ginagamit ang log mean temperature
Pag constant value ang U (overall heat transfer coefficient
Debye Huckel Theory
This theory was proposed by Peter debye and Eric huckel to explain the departure of electrolytic solution from ideality, because the electrolytic solution shows the deviation from the ideal behavior. Colligative properties of ideal solutions are directly proportional to the concentration of solute.
Used for low pressure and viscous fluids
Flowmeter
Kerogen
Oil shale
Used in cement production
ESP and Venturi
Difference between set point and experimental value
error
O2 needed per 100 m3 of CO & H2
Producer gas
part of turbulent velocity profile where v is constant
viscous sublayer
Lang factor for fluid processing
5.12
Lee/Kesler correlation is only applicable for
nonpolar and slightly polar
Measurement for low flow rate and high viscosity
Flowmeter
Alloy for standard definition of kilogram
Platinum/Iridium
Theoretical something
Transfer function
Collective term for disturbances in control
Perturbation
Producing heat from low temperature source
Heat pump
Difference of agitation from blending/mixing
agitation refers to forcing a fluid by mechanical means to flow in a circulatory or other pattern inside a vessel. Mixing usually implies the taking of two or more separate phases, such as a fluid and a powdered solid or two fluids, and causing them to be randomly distributed through one another.
Gravity Decanter
A gravity decanter is a vessel or stage in which two liquids of different densities are allowed to separate by gravity.
The feed is sent to a gravity decanter where the n-butanol phase separates from the aqueous phase and rises to the top.
A gravity decanter is used for the continuous separation of two immiscible liquids of differing densities.
A gravity decanter is a vessel or stage in which two liquids of different densities are allowed to separate by gravity.
If the membrane is broken and the gases diffuse, what is the change of entropy of the system if the gases act ideally?
delta S = Cpln T2/T1 - RlnP1/P2 = 0-1.986ln(4/2) = +1.376 Btu/moleR
(coulson) A forward feed double effect evaporator, having 10 m3 of heating surface in each effect, is used to concentrate 0.4 kg/s of caustic soda solution from 10 to 50 percent by mass. During a particular run, when the feed is 328 K, the pressures in two calandria are 375 and 180 kN/m2
(a) the load on the condenser
(b) the steam economy
(c) overall heat transfer coefficient in each effect
(a) 0.15 kg/s
(b)1.57 economy
(c) 2.53 kW/m2K and 1.84 kW/m2 K
(coulson) 1.4 m and of cross-sectional area 0.0045 m2, the concentrations measured at the inlet and outlet of the column are as shown in the figure
Determine the overall transfer coefficient and the height of the transfer unit
1.63 m
(coulson) Cool 100,000 kg/h of methanol from 95ŽC to 40ŽC, duty 4340 kW. Cooling water inlet
temperature 25ŽC and outlet temperature 40ŽC.
(a) Area required
(b) Channel velocity of Methanol
(c) Channel velocity of Brackish water
(a) 72.92
(b) 0.51 m/s
(c) 0.96 m/s
(himmelblau)
A limestone analysis:
CaCO2 92.89%
MgCO3 5.41%
Unreactive: 1.70%
(a) how many pounds of calcium oxide can be made from one ton of this limestone
(b) how many pounds of CO2 can be recovered per pound of limestone
(c) how many pounds of limestone are needed to make 1 tone of lime
(a) 1041 lb CaO/ton limestone
(b) 0.437 lb CO2/lb limestone
(c) 3550 lb stone/ton lime
(Coulson)
A packed tower is used for absorbing sulphur dioxide from air by means of a caustic
soda solution containing 20 kg/m3 NaOH. At an air flow of 2 kg/m2
s, corresponding to
a Reynolds number of 5160, the friction factor R/ρu2 is found to be 0.020. Calculate the mass transfer coefficient in kg SO2/s m2 (kN/m2
) under these conditions
if the tower is at atmospheric pressure. At the temperature of absorption, the diffusion
coefficient SO2 is 1.16 × 10−5 m2/s, the viscosity of the gas is 0.018 mN s/m2 and the
density of the gas stream is 1.154 kg/m3
.
7.56x10-4 kg SO2/m2s
(Coulson)
In an absorption tower, ammonia is absorbed from air at atmospheric pressure by acetic
acid. The flowrate of 2 kg/m2s in a test corresponds to a Reynolds number of 5100 and
hence a friction factor R/ρu2 of 0.020. At the temperature of absorption the viscosity of
the gas stream is 0.018 mN s/m2, the density is 1.154 kg/m3 and the diffusion coefficient
of ammonia in air is 1.96 × 10−5 m2/s. Determine the mass transfer coefficient through
the gas film in kg/m2s (kN/m2).
2.70x10-4 kg/m2s
you are asked to recommend, with reasons, the most suitable type of equipment for carrying out a gas-liquid reaction between a gas A and a solution of a reactant
(a) find Beta numerator
Beta numerator = 1.5x10-5
Bubble dispersion range (0.075 to 0.038)
Beta range (0.3 to 0.15)
liquid water in equilibrium with its vapor.
Total number of phase P = 2 (liquid and vapor) Total number of components C = 1( water) So degree of freedom F = C - P +2 = 1-2+2 = 1 Degree of freedom liquid water is equilibrium with its vapor
liquid water in equilibrium with a mixture of water vapor and nitrogen
2
a liquid solution of alcohol in water in equilibrium with its vapor
2
1.4 M3/S Flowrate From A Tank Is To Be Delivered To Another Tank. Using Parallel Flow, D1=0.6m And D2=0.4m
(a) velocity in d1=0.6
(b) velocity in d2=0.4
(c) what is the diameter if one pipe
(a) 3.636 m/s
(b) 2.97 m/s
(c) sqrt 0.891/D^2V
What element is used in the standard 1 kg measurement
Iridium
A hollow-fiber permeator with do=300 micros and d1 = 200 micron gives a water flux of 10 gal/day with 0.1M and the salt rejection is 97 percent. Feed solution flows normal to the fibers at an average superficial velocity of 0.5 cm/s. Is concentration polarization
0.068 since it is less than 1 then it might have significant polarization
A certain toaster has a heating element made of Nichrome wire. When the toaster is first
connected to a 120 V source (and the wire is at a temperature of 20.0C), the initial current is
1.80A. The current decreases as the heating element warm up. When the toaster reaches its final
operating temperature, the current is 1.53A. Find the power delivered to the toaster when it is at
its operating temperature.
P = VI = (120x1.53) = 183.6 W
When 1.61 x 10-3 moles of phenolphthalein indicators in dissolved in one liter of water plus
ethanol. Estimate the the concentration at equilibrium of [Hphth], [H3O+] and [phth-].
(pKa = 9.3 | Ka = 5x10-10 memorize K value of phenolphthalene)
ANS: [Hpth] = 1.599 x 10-3 M; [H30+] = 8.0 x 10-7 M; [phth-1] = 8.0 x 10-7 M
Chemical formula of Caffeine
C8H10N4O2
Titanium crystal. Unit cell. 147 pm Find Density
4.51
What are sigmatropic rearrangements to organic reactions
They are different from electrolytic reactions wherein movement of a sigma bond with a simultaneous rearrangement of the pi system does not occur
When travelling at NLEX at 80 mph, a stopped car is front causes you to suddenly skid to stop. What happened to the kinetic energy of the moving car?
All of it transferred to the road and sorrounding
Who theorized stars collapsing into blackhole as it increases entropy
Hawking
Discovered Helium
Ramsay and Travers
Access and predict the largest and smallest peak of a mass spectrum of two naturally occuring isotopes of hydrogen 18 with mass 1.00784 amu and abundance of 99.98858 and 28 iwth mass 2.0141 amu and abundance of 0.01158
A. 1.8 signal intensity at 24 atomic weight 1 signal inensity at 25 amu
Entropy
Gibbs and Boltzmann
pKa = 2.1. What type of acid?
strong acid (periodic table pka < 1)
How many different tetrapeptides can be made (a) if the peptides contain the residues of
asparagine, proline, serine, and methionine and (b) if all 20 amino acids can be used?
256, 160,000
Most oxidized form of nitrogen
Nitrates (No3-)
Oxidation number of O in Na2SO4
-2
how do two free radicals react when they encounter each other?
They unite with covalent bond formation
How to differentiate alkane alkene and alkyne?
reaction with Br2
A 1-kg copper bar (coeff of linear expansion = 17x106degC) is heated at atmospheric pressure from 20 to 50C. What is the change in internal energy (kJ) of the bar?
Version 2
What is the work (kJ) of the bar?
11.6
-17.36 kJ
Which of the following lipid contain a ceramide unit?
Sphingomyelins
Which of the following acidic group is present in taurine?
Sulfonic acid (-SO2OH)
The diamond has a face-centered cubic crystal lattice and there are eight atoms in a unit cell. Its density is 3.51 g/cm2. Calculaate the first six angles at which reflections would be obtained using an X-ray beam of wavelength 7.12 pm.
9.95, 11.50, 16.38, 19.31, 20.21, 23.51
color change of litmus paper when basic
blue
which among the compounds na di mo mahahanap ang C, N, H, and O in a single compound.
ascorbic acid
A railroad tank car is derailed and ruptured. it discharges 380 m3 of pesticide into the Mud Lake drain. Mud lake which has a liquid volume of 40,000 m3. The water in the creek has a flow rate 0.10 m3/s, a velocity of 0.10 m/s, and the distance from the spill site to the pond is 20 km. Estimate the time it will take to flush 99 percent of the pesticide from the pond.
Time to reach the pond = 2.3 days
time to flush - 21.3 or 21 days
Calculate the degree of deprotonation of the side chain of cysteine at pH 7.30, given that the
side chain –SH group has pKa = 8.20
0.126
Soln: 10(7.3-8.20)
Smoker equation sa distillation. When is it applicable?
relative volatility 1
Dittus boilter equation
turbulent
What is the friction due to an unseparated boundary layer
skin friction
inlet ay methane, ethane, 20% nitrogen, with x’s air. Orsat at 7.8% CO2, 7.4% O2, 84% N2.
Ilang percent ang methane sa fuel
57.3%
An equimolar mixture of benzene and toluene is subjected to a single batch distillation. Distillation is discontinued when 60% of the benzene in the feed is distilled. In the distillate the mole % of benzene is
66.6
Anong order ang di affected ng conc’n
Zero order
Ano daw po yung measuring device na does Not reach temp range of red hot objects 800-1600
radiation pyrometer
Other term for Viscose rayon:
regenerated cellulose acetate
What is unavailable to perform work
Entropy
Ano product sa cuproammonium process
Rayon fiber
Gas and liquid velocities are double ano raw mangyayari sa number of plates
Drlta G values ay -15 at -5 Choices X is faster than Y X is 3x faster than Y
Flash distillation is suitable for the separation of components
A. Having very close boiling points
B. Which form maximum boiling azeotrope
C. Having very wide boiling points
D. Which form minimum boiling azeotrope
C. Having very wide boiling points
Most efficient to dry banana chips
Hot and windy
LEAST flooding velocity: 25mm, plastic Pall 25mm B, 25mm smth, 16mm metal Pall
choose Highest Fp = lowest flooding velocity
Time needed to cool from 75-70 deg C= 10 mins
Time needed to cool from 70-65 deg C= ?
More than 10 mins (Newton’s law of cooling)
Sum of absorptivity and reflectivity of opaque
1
Drying w1= 0.45 w2 = 0.12 wc = 0.17 Xeq = 0.10 w1 to w2 ay 8h Ilang oras for 0.40 to 0.20
4.3
Fresh orange juice contains 12% (by weight) solids and the rest water 90% of the fresh juice is sent to an evaporator to remove water and subsequently mixed with the remaining 10%
0.7
Yung b constant ng Ammonia sa Van der Waal
b=RTc/8Pc
Priority of packings
Cost, Porosity, Size
HogNog concept If increase ang mass transfer, at increase ang surface area. Value ng height
unit?
Infinite Small Zero
May lumabas na ano daw yung extruded polystyrene na parang blue foam yung name
Styrofoam
May lumabas din about sa sa fanning friction, kung kelan ata mas icoconsider kailan daw i
coconsider yung fouling factor in heat tranfer eqpt design
Suspended solids in low velocity
Common Filter aid
diatomaceous earth
Which of ff will give the highest pressure drop?
90 degree elbow
Tas ung 200g coffee ground na given temp tas nilagay sa water ano daw final temp
200g coffee 100’C, + 50g tubig 0’C. Assume same Cp, resulting temp
8C
At 100°C ∆Hvap = 2257 Predict at 300°C
Steam table Saturated water kayo titingin
The radiation heat flux from a heating element at a temperature of 800C, in a furnace maintained at 300C is kW/m2. The fluc when the element temperature is increased to 1000C for the same furnace temperature is
16.5
At equal mass velocities, the values of film co-efficients for gases as compared to that for liquids are generally
a. higher
b. lower
c. same
lower
What DOES NOT happen kapag naglagay ng potassium sa water.
nothing happens
A pure drug is administered as a sphere and as a cube. The amount of drug is the same in the two tablets. Assuming that the shape and size do not influence the mass transfer, the ratio of rate of dissolution in water at t = 0 for the cubic to spherical tablet is
A. 0.54
B. 1.04
C. 1.24
D. 1.94
C. 1.24
