CHEMICAL ENGINEERING PRE-BOARD EXAMINATION NOVEMBER 2019
Day 1: Physical and Chemical Principles
Auxesis Review Center
Republic of the Philippines
SET A
INSTRUCTORS:
a) Choose the best answer to each question by shading the circle corresponding
to the letter of the correct answer.
b) Use number 2 pencil for shading the answers. DO NOT USE ballpoint pen.
c) Only PERRY’S CHEMICAL ENGINEERS’HANDBOOK (any edition) and the PERIODIC
TABLE OF ELEMENTS are allowed for open reference during the examination.
d) CASIO fx-991ES PLUS and all other programmable calculators are NOT ALLOWED.
Only one (1) calculator is allowed during the examination.
e) Cellphones or any similar devices are STRICTLY PROHIBITED at any time
during the examination.
f) Any reference mentioned in(c)with any kind of side notes written on or
inserted to it as found by the watcher before and during the examination
shall be immediately CONFISCATED.
g) Failure to conform to (e) and (f) shall automatically result to
DISQUALIFICATION of the examinee to continue with the examination.
----------------------------------------------------------------------------1.
In 1986, the nuclear reactor in Chernobyl had an accident and spewed
radioactive nuclei that were carried by the winds for hundreds of
miles. Today, among the child survivors of the event, the most common
damage is thyroid cancer. Which radioactive nucleus do you expect to
be responsible for these cancers?
a. I-131
c. I-123
b. I-129
d. I-125
2.
Which of the following objects are chiral?
a. pair of scissors
b. beaker
c. paper clip
d. the swirl created in water as it drains out of a sink or bathtub
3.
Perchloroethylene, which is a liquid at room temperature, is one of
the most widely used solvents for commercial dry cleaning. It is sold
for this purpose under several trade names, including Perclene. Does
this molecule have polar bonds? Is it a polar molecule? Does it have a
dipole?
a. yes, non-polar, yes
c. no, non-polar, none
b. no, non-polar, yes
d. yes, non-polar, none
4.
You place manganese, calcium chloride and sodium acetate in a liquid,
in which they are not soluble. The liquid has a density of 2.15 g/ml.
Which will sink to the bottom, which will stay on the top, and which
will stay in the middle of the liquid?
a. manganese, sodium acetate, calcium chloride
b. calcium chloride, manganese, sodium acetate
c. calcium chloride, sodium acetate, manganese
d. manganese, calcium chloride, sodium acetate
5.
In
of
a.
b.
photosynthesis, how many grams of CO 2 are required to produce 5.1 g
glucose?
8.8 kg
c. 6.3 kg
7.5 kg
d. 9.6 kg
6.
Classify these as kinetic or potential energy
(1) Water held by a dam
(2) A speeding train
(3) A book on its edge before falling
(4) A falling book
(5) Electric current in a light bulb
a. kinetic, kinetic, potential, kinetic, kinetic
b. kinetic, kinetic, potential, kinetic, potential
c. potential, kinetic, potential, kinetic, potential
d. potential, kinetic, potential, kinetic, kinetic
7.
We heat 50.0 g of an unknown substance by adding 205 cal, and its
temperature rises by 7.0°C. Identify the substance.
a. water
c. benzene
b. ethanol
d. acetic acid
8.
What process combines rubber and sulfur at a high temperature?
a. fulmination
c. fermentation
b. vulcanization
d. distillation
9.
Who invented the Carbon-14 dating method?
a. Irving Langmuir
c. August Hofmann
b. Williard Libby
d. Otto Hahn
10. Which of the following formula is red lead?
a. PbO
c. Pb2O4
b. Pb4O6
d. Pb3O4
11. Suppose that the yield of aspirin by the reaction is 75%. How many
grams
of salicylic acid would be required to give an actual yield of 25.0 g
of aspirin?
a. 43 g
c. 26 g
b. 12 g
d. 35 g
12. Predict which of these ionic compounds are soluble in water:
(1) MgCl2
(4) NH4NO3
(2) CaCO3
(5) Pb(OH)2
(3) Na2SO3
a. soluble, soluble, soluble, soluble, soluble
b. soluble, insoluble, soluble, soluble, insoluble
c. soluble, insoluble, insoluble, soluble, insoluble
d. soluble, insoluble, insoluble, soluble, insoluble
13. Polymer used in bullet proof vest
a. linear polyethylene
b. polyacrylonitrile
c. polycarbonate
d. polymethyl acrylate
For numbers 14 to 15:
A series of measurements of BOD for a sample of river water over
several days are tabulated below.
Day
BOD (mg/L)
2
70.0
5
102.4
7
111.0
8
114.0
10
118.8
14. Determine the BOD rate constant (in base e).
a. 0.42/day
c. 0.51/day
b. 0.36/day
d. 0.23/day
15. Determine the ultimate BOD.
a. 130 mg/L
c. 170 mg/L
b. 140 mg/L
d. 190 mg/L
16. A voltaic cell is represented by the following equation:
Fe(s) + Zn2+(aq)  Fe2+(aq) + Zn(s)
Which electrode is the anode and which electrode is the cathode?
a. Fe, Zn
c. Fe, Fe
b. Zn, Fe
d. Zn, Zn
17. The only natural amino acid that has no chiral center is:
a. Cysteine
b. Tryptophan
b. Proline
d. Glycine
18. The heat of combustion of methane, the major component of natural gas,
is 213 kcal/mol. The heat of combustion of propane, the major
component
of LPG or bottled gas, is 530 kcal/mol. On a kcal/mol basis, which of
these two fuels is the better source of heat energy? On a kcal/g
basis, which of these two fuels is the better source of heat energy?
a. propane, propane
c. propane, methane
b. methane, propane
d. methane, methane
19. If 3.3 g of a gas at 40°C and 1.15 atm pressure occupies a volume of
1.0 L, what is the mass of one mole of the gas?
a. 74
c. 89
b. 65
d. 52
20. Calculate the entropy change if 350 g of water at 5 0C is mixed with 500
g of water at 700C.
a. 3.33 eu
c. 5.05 eu
b. 6.67 eu
d. 4.49 eu
21. How to differentiate alkane alkene and alkyne?
a. combustion on an empty beaker
b. nature of carbon and its branching
c. reaction with Br2
d. all of these
22. Process of breaking down a large isotope into smaller isotopes.
a. nuclear fission
c. nuclear fusion
b. beta particle emission
d. gamma ray emission
23. Can a hydrogen bond form between
(1) Two molecules of methanol, CH3OH?
(2) Two molecules of formaldehyde, CH2O?
(3) One molecule of methanol, CH3OH, and one of formaldehyde,
CH2O?
a. yes, yes, yes
c. no, yes, no
b. yes, no, yes
d. yes, no, no
24. What will happen to ice at 0°C if the pressure decreases from 1 atm to
0.001 atm?
a. it becomes vapor
c. it becomes liquid
b. it remains solid
d. both a and c are possible
25. How does alpha, beta and gamma particle affect the mass number of an
atom?
a. 4, 1, 0
c. 4, 0, 0
b. 4,-1, 0
d. 2,-1, 0
26. Notation on alkane containing Cl
a. chloro
b. chloride
c. chlorate
d. chloric
27. In an autoclave, a constant amount of steam is generated at a constant
volume. Under 1.00 atm pressure, the steam temperature is 100°C. What
pressure setting should be used to obtain a 165°C steam temperature
for the sterilization of surgical instruments?
a. 2.3 atm
c. 1.8 atm
b. 1.2 atm
d. 2.6 atm
28. What was Melvin Calvin was known for his study of?
a. x-rays
c. magnetics
b. photosynthesis
d. boiling point
29. Using the equilibrium constants given for reactions (1) and (2), what
is the equilibrium constant for reaction (3)?
(1) 2NO(g) + O2(g) → N2O4(g) Kp = 1.49 × 1013
(2) 2NO(g) + O2(g)→ 2NO2(g)
Kp = 1.66 × 1012
(3) N2O4(g) → 2NO2(g)
a. 0.0123
c. 0.111
b. 8.98
d. 80.3
30. Which of the
of soap?
a. A soap is
b. A soap is
c. A soap is
d. A soap is
following is the best definition of the chemical nature
a very long molecule.
a long chain carboxylic acid.
an ester of glycerol and a long chain carboxylic acid.
a salt of a long chain carboxylic acid.
31. Iodine vapor forms iodine crystals when it touches a cold surface.
What is the reverse of the process being described?
a. deposition
c. fusion
b. condensation
d. sublimation
32. Balancing C2H5SH + O2 → CO2 + H20 + SO
a. 1, 8, 4, 5, 1
c. 2, 7, 4, 4, 2
b. 2, 9, 4, 6, 2
d. 1, 5, 4,3, 1
33. Given: Dodecane
(1) Is it soluble in water?
(2) Is it soluble in hexane?
(3) Is it combustible?
(4) Is it solid, liquid or gas at room temperature and atmospheric
conditions?
(5) Is it denser than water?
a. no, yes, yes, liquid, less dense
b. no, yes, yes, gas, denser
c. no, yes, no, liquid, less dense
d. no, no, yes, gas, dense
34. Which of the following has a larger ionic nucleus? Na+ or Na?
a. Both
c. Na+
b. Na
d. none of these
35. The purpose of control rods in a fission reactor is to:
a. cool down the reactor fuel.
b. prevent oxygen from reaching the fuel.
c. absorb neutrons generated in the fission process.
d. absorb electrons emitted in the fission process.
36. What compound is a ketone but it is not a carbohydrate but is useful
commercially?
a. ethyl alcohol
c. glucose
b. aldehyde
d. acetone
37. Which bond is the least polar? C-C, C-N, C-Cl, C-F, C-O?
a. C-C < C-Cl < C-N < C-O < C-F
c. C-F < C-N < C-C < C-Cl < C-O
b. C-Cl < C-N < C-C < C-F < C-O
d. C-O < C-N < C-F < C-C < C-Cl
38. Which Republic Act is the PRC Modernization Act of 2000?
a. R.A. 8750
c. R.A. 8890
b. R.A. 7897
d. R.A. 8981
39. You are presented with a Lewis dot structure of element X as X. To
which two groups in the Periodic Table might this element belong?
a. Group 2 A
c. Group 1 A
b. Group 7 A
d. Group 4 A
40. The molar volume of benzene(l) is 88.9 cc at 20°C and 1 atm pressure.
Find the value of ΔG for the compression of 1 mole of the liquid from
1 to 100 atm.
a. 254 calories
c. 222 calories
b. 287 calories
d. 213 calories
41. A radioactive isotope with an intensity (activity) of 100 mCi per vial
is delivered to a hospital. The vial contains 10 mL of liquid. The
instruction is to administer 2.5 mCi intravenously. How many
milliliters of the liquid should be administered?
a. 0.66 ml
c. 0.40 ml
b. 0.18 ml
d. 0.25 ml
42. Diving,
particularly
SCUBA
(Self-Contained
Underwater
Breathing
Apparatus) diving, subjects the body to increased pressure. Each 10 m
(approximately 33 ft) of water exerts an additional pressure of 1 atm
on the body. What is the partial pressure of oxygen in the air in the
lungs at a depth of 100 ft?
a. 0.83 atm
c. 3.1 atm
b. 4.0 atm
d. 0.77 atm
43. The solubility of aspartic acid in water is 0.500 g in 100 mL at 25°C.
If we dissolve 0.251 g of aspartic acid in 50.0 mL of water at 50°C
and let the solution cool to 25°C without stirring, shaking, or
otherwise disturbing the solution, would the resulting solution be a
saturated, unsaturated, or supersaturated solution?
a. saturated
c. supersaturated
b. unsaturated
d. cannot be determined
44. A certain liquid has a viscosity of 0.0001 poise and a density of 3.2
g/ml. How long will it take for platinum ball with 2.5 mm radius to
fall 1 cm through the liquid? The density of the platinum is 21.4
g/ml.
a. 33.4 s
c. 28.4 s
b. 40.5 s
d. 48.9 s
45. The heat of vaporization of liquid Freon-12, CCl2F2, is 4.71 kcal/mol.
Calculate the energy required to vaporize 39.2 g of this compound. The
molecular weight of Freon-12 is 120.9 amu.
a. 1.53 kcal
c. 1.98 kcal
b. 1.12 kcal
d. 1.67 kcal
46. Microwaves are a form of electromagnetic radiation that is used for
the rapid heating of foods. What is the frequency of a microwave with
a wavelength of 5.8 cm?
a. 3.6x109 /s
c. 5.2x109 /s
b. 9.4x109 /s
d. 1.7x109 /s
47. Water on heating from 1 to 4°C
a. contracts
b. has same volume
48. This law explains
incinerate”.
why
aerosol
c. expands
d. may contract or expand
cans
carry
the
warning
“Do
not
a. Charles Law
b. Gay-Lussac Law
c. Boyles Law
d. Daltons Law of Partial Pressure
49. A teardrop with a volume of 0.5 mL contains 5.0 mg salt. What is the
molarity of the salt in the teardrop?
a. 0.4 M
c. 0.1 M
b. 0.3 M
d. 0.2 M
50. How much work is done when a man weighing 75 kg climbs the Washington
monument, 555 ft high? How many kilocalories must be supplied to do
this muscular work, assuming that 25% of the energy produced by the
oxidation of food in the body can be converted into muscular work?
a. 254 kcal
c. 119 kcal
b. 380 kcal
d. 476 kcal
51. The normal boiling point of a substance depends on both the mass of
the molecule and the attractive forces between molecules. Arrange the
compounds in each set in order of increasing boiling point: (1) HCl,
(2) HBr and (3) HI.
a. HI < HBr < HCl
c. HCl < HBr < HI
b. HCl < HI < HBr
d. HI < HCl < HBr
52. Trichlorofluoromethane (Freon-11, CCl3F) as a spray is used to
temporarily numb the skin around minor scrapes and bruises. It
accomplishes this by reducing the temperature of the treated area,
thereby numbing the nerve endings that perceive pain. Calculate the
heat in kilocalories that can be removed from the skin by 1.00 mL of
Freon-11. The density of Freon-11 is 1.49 g/mL, and its heat of
vaporization is 6.42 kcal/mol.
a. 7x10-2 kcal
c. 5x10-2 kcal
b. 1x10-2 kcal
d. 3x10-2 kcal
53. Which isotope of
boron-12?
a. boron-8
b. boron-10
boron is
the most
stable: boron-8,
boron-10, or
c. boron-12
d. both a and b
54. Balloons now are used to move huge trees from their cutting place on
mountain slopes to conventional transportation. Calculate the volume
of a balloon needed if it is desired to have a lifting force of 1000
kg when the temperature is 290 K at 0.940 atm. The balloon is to be
filled with helium. Assume that air is 80 mol % N2 and 20 mol % O2.
Ignore the mass of the superstructure and propulsion engines of the
balloon.
a. 1020 m3
c. 1530 m3
3
b. 1480 m
d. 1660 m3
55. Suppose that on another planet where the atmosphere is ammonia that
the pressure on the surface, at h = 0, is 400 Torr at 250 K. Calculate
the pressure of ammonia at a height of 8000 m. The planet has the same
g value as the earth.
a. 100 Torr
c. 210 Torr
b. 130 Torr
d. 220 Torr
56. According to the label on a piece of cheese, one serving of 28 g
provides the following daily values: 2% of Fe, 6% of Ca, and 6% of
vitamin A. The recommended daily allowances (RDA) of each of these
nutrients are as follows: 15 mg Fe, 1200 mg Ca, and 0.800 mg vitamin.
Calculate the concentrations of each of these nutrients in the cheese
in ppm.
a. 5 ppm
c. 15 ppm
b. 10 ppm
d. 20 ppm
57. What is the specific gas constant of dry air in J/kg per unit Kelvin?
a. 0.287
b. 28.7
c. 2.87
d. 287
58. Write an equation for the reaction of HCl with each compound. Which
are acid–base reactions? Which are redox reactions?
(1) Na2CO3
(5) Fe2O3
(2) Mg
(6) CH3NH2
(3) NaOH
(7) NaHCO3
(4) NH3
a. none
c. only (2)
b. (1), (2) and (7)
d. only (6)
For numbers 59 to 60:
59. An ice cube at 0 °C weighing 100.0 g is dropped into 1 kg of water at
20 °C. Does all of the ice melt? If not, how much of it remains? The
latent heat of fusion of ice at 0 °C is 6.025 kJ/mol, and the molar
heat capacity of water, CP is 75.3 J/mol-K.
a. 100 g
b. 75 g
c. 58 g
d. 12 g
60. Perform the same calculations with 10 ice cubes of the same size
dropped into the water.
a. 1000 g
c. 580 g
b. 750 g
d. 120 g
61. A solution of calcium chloride is prepared in a 1.00-L volumetric
flask. A 60.00-g sample of CaCl2 is added to a small amount of water in
the flask, and then additional water is added to bring the total
volume of solution to 1.00 L. What is the concentration of calcium
chloride in units of molarity?
a. 0.29 M
c. 0.38 M
b. 0.61 M
d. 0.54 M
62. Classify the following systems as homogeneous, heterogeneous, or
colloidal mixtures.
(1) Physiological saline solution
(2) Orange juice
(3) A cloud
(4) Wet sand
(5) Suds
(6) Milk
a. homogeneous, homogeneous, homogeneous, heterogeneous, colloidal,
homogeneous
b.
homogeneous,
heterogeneous,
colloidal,
heterogeneous,
heterogeneous, colloidal
c. homogeneous, heterogeneous, colloidal, heterogeneous, colloidal,
colloidal
d. homogeneous, homogeneous, homogeneous, heterogeneous, colloidal,
colloidal
63. Calculate the degree of dissociation for a 0.010-m solution of HCl
that freezes at 273.114 K.
a. 0.96
c. 0.88
b. 0.94
d. 0.80
64. Assume that the following exothermic reaction is at equilibrium:
H2(g) = I2(g) +2HI(g)
Tell whether the position of equilibrium will shift to the right or
the left if we
(1) Remove some HI
(2) Add some I2
(3) Remove some I2
(4) Increase the temperature
(5) Add a catalyst
a. right, right, left, left, no shift
b. right, left, left, right, no shift
c. left, left, right, right, no shift
d. right, right, left, right, right
65. In an endothermic reaction, the activation energy is 10.0 kcal/mol. Is
the activation energy of the reverse reaction also 10.0 kcal/mol, or
would it be more or less?
a. less
c. more
b. the same
d. cannot be determined
66. Balance the chemical equation given K 4Fe(CN)6 + H2SO4 + H2O = K2SO4 +
FeSO4 + (NH4)2SO4 + CO
a. 1,6,6,2,1,3,6
c. 6,3,1,2,6,6,1
b. 2,6,6,2,1,3,6
d. 1,6,6,2,1,2,6
67. Calculate the mole fraction solubility of naphthalene at 25 °C in a
liquid with which it forms an ideal solution. The ΔfusH = 19.0 kJ/mol
for naphthalene at 25 °C. Its normal melting point is 80.2 °C.
a. 0.228
c. 0.415
b. 0.302
d. 0.567
68. Suppose you have an aqueous solution prepared by dissolving 0.050 mol
of NaH2PO4 in 1 L of water. This solution is not a buffer, but suppose
you want to make it into one. How many moles of solid NaH 2PO4 must you
add to this aqueous solution to make it into a buffer of pH 7.21.
a. 0.05 mol
c. 0.0005 mol
b. 0.5 mol
d. 0.005 mol
69. _______
is
a
rather
disagreeable-smelling
liquid
preservative for laboratory specimens.
a. Acetaldehyde
c. Methanal
b. Methanol
d. Valeraldehyde
used
70. Reactions proceeds spontaneously at low temperatures.
temperatures, the reverse reaction becomes spontaneous.
a. + Δ H and + ΔS
c. - Δ H and + ΔS
b. - Δ H and – ΔS
d. + Δ H and – ΔS
At
as
a
high
71. What is the common name of this compound – C6H5OCH3?
a. Aniline
c. Cumene
b. Styrene
d. Anisole
72. The influence of mixing of s and p orbitals; the greater the fraction
of s character of the hybrid orbital, the more electronegative is the
atom
a. Hybridization
c. Hybridization Effect
b. Hybrid Orbitals
d. Hybrid
73. Name the Alkane
CH3
CH3
H2C
CH
H3C
CH
CH
CH3
a.
2-ethyl-3,4-dimethylpentane
b. 3,4,5-trimethylhexane
c.
4-ethyl-2,3-dimethylpentane
d. 2,3,4-trimethylhexane
CH3
74. For each of the following, identify the radiation emitted.
(1) Beryllium-10 changes to boron-10
(2) Europium-151m changes to europium-151
(3) Thallium-195 changes to mercury-195
(4) Plutonium-239 changes to uranium-235
a. alpha, gamma, positron, beta
c. beta, gamma, alpha, positron
b. alpha, gamma, beta, positron
d. beta, gamma, positron, alpha
75. Electrolysis of molten KBr generates bromine gas, which can be used in
industrial bromination processes. How long will it take to convert a
500.00-kg batch of phenol (C6H5OH) to monobromophenol using a current
of 20 000 A?
a. 10.1 hr
c. 14.2 hr
b. 12.8 hr
d. 15.6 hr
76. A 5.00 mL aliquot of bleach (density = 1.61 g/mL) was diluted and
treated with excess KI to convert hypochlorite to chloride. The
liberated I2 required 22.85 mL of 0.214 M Na2S2O3 for titration.
Calculate the % ClO–in the bleach.
a.4.18%
c. 2.72%
b.1.56%
d. 3.12%
77. Balance the chemical equation K4Fe(CN)6
Fe2(SO4)3 + MnSO4 + HNO3 + CO2 + H2O
a. 60,60,188,10,122,299,162,5,122
b. 122,299,162,5,122,60,60,188,10
c. 188,60,60,122,5,162,299,122,10
d. 10,122,299,162,5,122,60,60,188
+
KMnO4
+
H2SO4
=
KHSO4
+
78. A base mixture sample weighing 976 mg was dissolved in sufficient
water to make 100 mL solution and divided into two equal portions. The
first portion was titrated with 52.05 mL of 0.1004M HCl to the methyl
red end point. The other portion was titrated with 23.02 mL of the
acid to the phenolphthalein endpoint. Calculate the % composition of
sample.
a. 50.16% NaHCO3, 50.20% Na2CO3
c. 10.38% NaHCO3, 50.20% Na2CO3
b. 23.90% NaHCO3, 50.20% Na2CO3
d. 18.94% NaHCO3, 62.70% Na2CO3
79. What is the major product of the reaction?
⃗
1. HNO3 ⃗
1. Fe
2. H 2 SO4 2. HCl
⃗
1. HNO2 ⃗
1. Cu2 ( CN )2
2. low temp
2. heat
a. Aniline
b. Benzonitrile
c. Benzene
d. Iodobenzene
80. An environmental engineering student was very interested in the
reaction of the chemical 2,4,6-chickenwire. She went into the lab and
found that 2,4,6-chickenwire degrades in water. During her experiments
she collected the data in the following table. Determine if the
reaction is zero-, first-, second-, third-order with respect to the
concentration of 2,4,6-chickenwire.
Time, min
0
1
2
4
8
a. zero
b. first
Concentration, mg/L
10.0
8.56
8.14
6.96
6.77
Time, min
10
20
40
880
c. second
d. third
Concentration, mg/L
5.46
4.23
1.26
0.218
81. The phosphate in a 3000 mg sample of industrial detergent was
precipitated by the addition of 1-gram AgNO3. The solution was filtered
and the filtrate required 18.23 mL of 0.1377 M KSCN. Calculate the
percentage of phosphate in the detergent. AgNO3 (169.87 g/mol) PO4–3
(94.97 g/mol)
a. 3.56%
c. 7.12%
b. 5.35%
d. 10.69%
82. The difference between the actual property value of a solution and the
value it would have as an ideal solution at the same T and P and
composition is called
a. Residual
c. Excess
b. Partial property
d. Gibbs free energy
83. The Waramurungundi tannery with a wastewater flow of 0.011 m 3/s and a
BOD5 of 590 mg/L discharges into the Djanggawul Creek. The creek has a
10-year, 7-day low flow of 1.7 m3/s. Upstream of the Waramurungundi
tannery, the BOD5 of the creek is 0.6 mg/L. The BOD rate constants (k)
are 0.115 day−1 for the Waramurungundi tannery and 3.7 day−1 for the
creek. Calculate the initial ultimate BOD after mixing.
a. 9.27 mg/L
c. 6.05 mg/L
b. 8.41 mg/L
d. 3.16 mg/L
84. Calculate the weight of primary standard Na 2C2O4 (134 g/mol) necessary
to react with 25 mL of 0.2005 M KMnO4 in acidic medium.
a. 0.671 gram
c. 1.343 grams
b. 1.679 grams
d. 2.687 grams
85. The Bailey Stone Works employs six people. Assuming that the density
of uncompacted waste is 480 kg · m−3, determine the annual volume of
solid waste produced by the stone works assuming a waste generation
rate of 1 kg · capita−1 · day.
a. 3.8 m3/yr
c. 4.6 m3/yr
3
b. 1.9 m /yr
d. 2.2 m3/yr
86. Hypochlorous acid decays in the presence of ultraviolet radiation.
Assume that degradation occurs according to first-order kinetics and
the rate of degradation was measured to be 0.12 day−1 (at a particular
sunlight intensity and temperature). Given this, how long does it take
for the concentration of hypochlorous acid to reach nondetectable
levels (0.05 mg/L) if the initial concentration were 3.65 mg/L?
a. 25 days
c. 36 days
b. 14 days
d. 47 days
87. The company you work for plans to release a waste stream containing
7.0 mg/L of benzaldehyde. calculate the theoretical carbonaceous
oxygen demand of this waste stream (in mg/L).
a. 17 mg/L
c. 19 mg/L
b. 11 mg/L
d. 14 mg/L
88. A 0.0722 M acid has pH of 3.11, what is the Ka of the acid?
a. 4.2 x 10-6
c. 8.35 x 10-6
-7
b. 8.35 x 10
d. 4.2 x 10-7
89. The Nairyosangha landfill located in Peshdadians serves a population
of 562,400 people generating MSW at a rate of 1.89 kg · capita −1 · day.
The volume of the landfill is 11,240,000 m 3. At the present time, 63%
of the landfill is used. The ratio of cover to compacted fill is 1.9.
Determine projected life remaining for the landfill.
a. 3 years
c. 5 years
b. 6 years
d. 4 years
90. Assume the density of the compacted waste to be 490 kg · m−3. What is
the ratio of HPO42- /H2PO4- in a phosphate buffer of pH 7.9 (the pH of
human pancreatic fluid)?
a. 3:1
c. 1:1
b. 4:1
d. 5:1
91. The discharge from the Renenutet sugar beet plant causes the DO at the
critical point to fall to 4.0 mg/L. The Meskhenet Stream has a
negligible BOD and the initial deficit after the river and wastewater
have mixed is zero. What DO will result if the concentration of the
waste (Lw) is reduced by 50%? Assume that the flows remain the same
and that the saturation value of DO is 10.83 mg/L in both cases.
a. 6.1 mg/L
c. 8.9 mg/L
b. 7.4 mg/L
d. 9.3 mg/L
92. Following are pH ranges for several human biological materials. From
the pH at the midpoint of each range, calculate the corresponding
[H3O-]. Which materials are acidic?
(1) Milk, pH 6.6–7.6
(2) Gastric contents, pH 1.0–3.0
(3) Spinal fluid, pH 7.3–7.5
(4) Saliva, pH 6.5–7.5
(5) Urine, pH 4.8–8.4
(6) Blood plasma, pH 7.35–7.45
(7) Feces, pH 4.6–8.4
(8) Bile, pH 6.8–7.0
a. 1, 4, 7, 8
c. 2, 5, 7, 8
b. 2, 5, 6, 7
d. 1, 3, 7, 8
93. A water contains 100.0 mg/L CO2−3 and 75.0 mg/L HCO−3 at a pH of 10 (T =
25◦C). Calculate the exact alkalinity. Approximate the alkalinity by
ignoring the appropriate chemical
species.
a. 167 mg/L
c. 459 mg/L
b. 233 mg/L
d. 385 mg/L
94. A landfill that is 12 ha in area has a liner of thickness 0.9 m. Each
year 1700 m3 of leachate is collected. The hydraulic conductivity of
the liner is 3.9 × 10−10 m · s −1. What is the head of water above the
liner?
a. 2 m
c. 1 m
b. 3 m
d. 4 m
95. What concentration of Al2(SO4)3 has the same ionic strength as 0.1 M
NaCl?
a. 1.7x10-2 M
c. 2.5x10-2 M
-2
b. 3.3x10 M
d. 6.7x10-2 M
96. Calculate the NBOD of glutamic
glutamic acid is 0.1 mM.
a. 5.8 mg/L
b. 6.4 mg/L
acid.
Assume
the
concentration
of
c. 8.1 mg/L
d. 2.3 mg/L
97. Above the stratosphere, the concentration of ozone and other gases is
low, and the temperature decreases with increasing altitude
a. troposphere
c. mesosphere
b. stratosphere
d. ionosphere
98. How many grams of urea must be added to 4000 grams of water to make
the solution boil at 100.320C?
a. 75.3 grams
c. 150.5 grams
b. 185.4 grams
d. 205.6 grams
99. What is the solubility of CaF2 in water in mols of CaF2 per L of
solution? Ksp for CaF2 is 1.7 × 1010.
a. 9.2×10—6 M
c. 1.3×10—5 M
—4
b. 3.5×10 M
d. 5.5×10—4 M
100. You work in a lab and it is known that radioactivity is being emitted
with an intensity of 175 mCi at a distance of 1.0 m from the source.
How far, in meters, from the source should you stand if you wish to be
subjected to no more than 0.20 mCi?
a. 30 m
c. 40 m
b. 10 m
d. 20 m