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PROB SOLVING PBE > 1. REFRESHER > Flashcards

1. REFRESHER Flashcards

1
Q

The following reactions is important in lake and river sediments that are devoid of oxygen
SO42- + H+ + CH2O → HS- + CO2 + H2O
Balance this equation.

A

1, 1, 2, 1, 2, 2

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2
Q

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

ANSWER: Anode = Fe and Cathode = Zn

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3
Q

Distance from the earth to the most remote known normal galaxies is calculated to be:

A

9x1025 m

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4
Q

Mean distance from the equator to the north pole is:

A

1x107 m

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5
Q

Determine the volume in mL of 1mol of pure
ethyl alcohol.

A

ANSWER: 58 mL

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6
Q

If high octane gasoline with density 0.71 is used by a BMW on NLEX to travel to Tarlac 125 mi away and a gas mileage of 19.75 mi/gal estimate the quantity in kg of carbon dioxide produced.

A

52 kg

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7
Q

Iodine vapor forms iodine crystals when it touches a cold surface. What is the reverse of the process being described?

A

sublimation

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8
Q

What is the chemical formula of aspirin?
A. C8H9O3 C. C8H13O5
B. C9H8O4 D. C10H34O

A

ANSWER: B. C9H8O4

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9
Q

Which of the following formula is red lead?
A. PbO C. Pb2O4
B. Pb4O6 D. Pb3O4

A

ANSWER: D. Pb3O4

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10
Q

What is the common name of this compound C6H5OCH3?
A. Aniline C. Cumene
B. Styrene D. Anisole

A

ANSWER: D. Anisole

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11
Q

What is the formula of melamine?
A. C3H6N6 C. C4H7N8
B. C3H8N6 D. C4H8N6

A

ANSWER: A. C3H6N6

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12
Q

Calculate the mass of titanium in kilograms in 0.4011 million grams of TiCl4.

A

ANSWER: 101

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13
Q

Author of Octet Rule

A

ANSWER: Gilbert Lewis

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14
Q

Who discovered EDTA?

A

ANSWER: Ferdinand Munz

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15
Q

The Nobel Prize for radioactivity discovery was shared between Curie and Roentgen. Who coined the word “Serendipity” in 1754?

A

ANSWER: Horace Walpole

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16
Q

Who invented vulcanized rubber?

A

ANSWER: Charles Goodyear

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17
Q

Who discovered the structure of benzene?

A

ANSWER: Friedrich August Kekule

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18
Q

Who is the father of Quantum Theory?

A

ANSWER: Max Planck

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19
Q

Who discovered x-ray?

A

ANSWER: Wilhelm Conrad Roentgen

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20
Q

What was Melvin Calvin was known for his study of?

A

ANSWER: photosynthesis

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21
Q

What discovered Deuterium?

A

ANSWER: Harold C. Urey

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22
Q

Father of nuclear chemistry and discovered proof of nuclear fission.

A

ANSWER: Otto Hann

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23
Q

Who discovered carbon dating?

A

ANSWER: Willard Libby

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24
Q

In an experiment it was found that the total charge on an oil drop was 5.93x10-18 C. How many negative charges does the drop contain?

A

ANSWER: D. 37

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25
Q

Estimate the energy emitted per photon as well as the quantity of photons emitted per second from a one hundred watt yellowlight bulb with y = 550 nm and a one kilowatt microwave source with y = cm emitting 1.99 x 10-23 J per photon and 5.03 x 10 25 photons/sec/
A. 3.60 x 10-19 J and 2.77 x 1020 photons /sec
B. 2.620 x 10-18 J and 3.11x 1021 photons /sec
C. 3.91 x 10-20 J and 4.22 x 1019 photons /sec
D. 4.11 x 10-20 J and1.67 x 1020 photons /sec

A

A. 3.60 x 10-19 J and 2.77 x 1020 photons /sec

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26
Q

Determine which of the following will float or sink in water: balsa wood, ethylene glycol, table salt, ethanol
A. float, float, float, float
B. float, sink, sink, float
C. sink, float, sink, float
D. sink, sink, sink, sink

A

B. float, sink, sink, float

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27
Q

What other particle is formed in the fusion of two protons to yield deuterium?

A

neutron

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28
Q

Which isotope is produced when Polonium-216 decays by emitting an alpha particle followed by two beta particles?

A

Polonium-212

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29
Q

Process of breaking down a large isotope into smaller isotopes.
A. nuclear fission
B. beta particle emission
C. nuclear fusion
D. gamma ray emission

A

A. nuclear fission

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30
Q

When a thorium-230 atom undergoes alpha decay, the products of the reaction are usually:
A. Radium and an alpha particle
B. Actinium and an alpha particle
C. Actinium and a positron
D. Radium and a positron

A

ANSWER: A. Radium and an alpha particle

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31
Q

Balance the following equation: 225Ac82 = ? + 4He2; when one alpha particle is lost from actinium.
A. 221Ac85 = 217Fr83 + 4He2
B. 225Ac89 = 221Fr87 + 4He2
C. 225Ac82 = 226Fr83 + 4He2
D. 223Ac91 = 233Fr91 + 4He2

A

B. 225Ac89 = 221Fr87 + 4He2

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32
Q

Determine the number of days it will take for one milligram of rubidium to decay to 0.6 mg.
A. 132 C. 63
B. 98 D. 211

A

63

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33
Q

Determine the age of the mineral sample which contains 50.05 mg of 238 Uranium and 14.05 mg of 206 lead. Assume a half-life for the process of 238 U and 206 Pb at 4.52 x109 years.
A. K = 1.50 x10-10 per year; 75.2 mg 238 U; 2.20 x109 years old
B. K = 1.80 x10-9 per year; 66.2 mg 238 U; 1.80 x109 years old
C. K = 0.90 x10-8 per year56.1 mg 238 U; 1.30 x109 years old
D. K = 2.10 x10-10 per year; 87.1 mg 238 U; 2.80 x109 years old

A

B. K = 1.80 x10-9 per year; 66.2 mg 238 U; 1.80 x109 years old

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34
Q

Draw the condensed and skeletal structures of diethyl ether which is used by most doctors and hospitals as an anesthetic during operations.
A.C2H5OC2H5 C.C5H10O
B.C6H6O6 D.CH3CH2OCH2CH3

A

D.CH3CH2OCH2CH3

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35
Q

It is an organic reaction that converts an alcohol into an alkyl chlorine using triphenylphosphine and carbon tetrachloride.

A

Appel Reaction

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36
Q

What compound can be used to convert alcohol or a phenol into an ester?
A. Acetic anhydride: CH3-C-O-COCH3
B. Benzamide
C. Maleic anhydrate: CH3-CH2-COO-CH3
D. Aqueous bromine solution

A

A. Acetic anhydride: CH3-C-O-COCH3

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37
Q

Explain the differences in structure between a saturated hydrocarbon from an unsaturated hydrocarbon.
A. Any of these
B. A saturated hydrocarbons contains only carbon-carbon single bonds, while an unsaturated hydrocarbon contains one or more carbon-carbon double or triple bonds.
C. A saturated hydrocarbon is used mainly in cheaper forms of gasoline for vehicle use, while unsaturated hydrocarbons composed most of the gasoline formulas, used by current gasoline manufacturers.
D. A saturated hydrocarbon can no longer accept any hydrocarbon or inorganic element and compound, while an unsaturated hydrocarbon is more of flexible in reaction mechanisms.

A

B. A saturated hydrocarbons contains only carbon-carbon single bonds, while an unsaturated hydrocarbon contains one or more carbon-carbon double or triple bonds.

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38
Q

Which of the following is a primary application of ethylene?
A. Production of plastics and synthetic fibers
B. Use as a plant hormone for ripening of fruits
C. Use as a fuel in industrial applications
D. Use as a refrigerant in cryogenic applications

A

B. Use as a plant hormone for ripening of fruits

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39
Q

What structural characteristics do citric acid and malic acid have in common?
A. They are heterocyclic compounds
B. Both has three moieties of carboxylic acid
C. They contain an alkene bridge
D. They are both hydroxy acids

A

D. They are both hydroxy acids

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40
Q

Adrenaline is produced in the body through a biochemical nucleophilic substitution reaction where:
A. The leaving groups are larger and more complex than the halogen atoms frequently in nucleophilic substitution reactions.
B. According to Markovnikov’s rule, the biosynthesis of epinephrine adds hydrogen atoms to the double banded carbon atom.
C. The nucleophilic nitrogen atom of norepinendrine from a covalent bond with the CH3 of S adenosylmethionine
D. The reactant neocleophile atom replaces the leaving group in the nucleophylic substitution reaction.

A

D. The reactant neocleophile atom replaces the leaving group in the nucleophylic substitution reaction.

41
Q

What organic product is formed when C6H5CH2COOH is treated with CH3OH + H2SO4 (catalyst)?
A. C6H5CH2CH2OH
B. C6H5CH2C00-Na+ + CO2 + H20
C. C6H5CH2C00-NH4
D. C6H5CH2CO2CH3 + H20

A

D. C6H5CH2CO2CH3 + H20

42
Q

In a dehydration reaction where water is lost, an organic compound C3H8O reacts with concentrated phosphoric acid and a product is formed. This product rapidly decolorizes a solution of bromine in tetrachloromethane. What is this product?

A

Propene

43
Q

These compounds are formed by the reaction of acids with alcohols.

A

Esters

44
Q

Fatty acid such as lauric acid and palmitic acid and oleic acid are long unbranched carboxylic acids consisting of 12 to 20 carbon atoms. Which type of fatty acid should people avoid ingesting, saturated or unsaturated and why?

A. Saturated, because the risk of cardiovascular disease is increased
B. Fatty acids are safe to ingest
C. Unsaturated, because the risk of cardiovascular disease is increased
D. Both fatty acids, because the risk of cardiovascular disease is increased

A

A. Saturated, because the risk of cardiovascular disease is increased

45
Q

The person’s sense of smell and taste depend on specific biochemic receptors present in a person’s nose and mouth. In 2004, a Nobel Prize was given to the researchers who established this fact and identified the the type of organic compound associated with the sense of smell and taste. The chemical identified was;

A

rhodopsin

46
Q

Name the major physiologically active substances that comes from: bark of the willow tree, the pituitary gland, the sap of the poppy and the belladenna plant.
A. Cocaine, reserpine, salicin, atropine
B. Reserpine, atropine, B-endorphine, opium
C. Opium, cocaine, salicin, and reserpine
D. Salicin, beta-endomorphin, opium, atropine

A

D. Salicin, beta-endomorphin, opium, atropine

47
Q

It is the major component of lecithin.

A

Phosphatidylcholine

48
Q

Taurine, a Beta amino acid belongs to the acidic group of:
A. –SO2OH C. –COOH
B. –COONH3 D. –C=OH

A

A. –SO2OH

49
Q

In the study of fats and lipids, determine which of the two triglycerides has a higher melting point? Substance A containing only lauric acid and glycerol, or substance B-containing only stearic acid and glycerol?
A. Both have the same melting points
B. B
C. A
D. None of these

A

B. B

50
Q

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.

A

0.11

51
Q

Define is DNA? RNA?
A. Beta ribose phosphoric acid and 1,2 ribonucleic acid
B. Deoxyribonucleic acid and ribonucleic acid
C. Di-oxyl nucleic acid and cystosine
D. 1,2-deoxyribose and cystosine

A

B. Deoxyribonucleic acid and ribonucleic acid

52
Q

Glucose is the only carbohydrate compound that the brain can use for energy. Which pathway is mobilized to supply the need of the brain during starvation?
A. gluconeogenesis C. glycogenesis
B. glycolysis D. none of these

A

A. gluconeogenesis

53
Q

Predict the order of the melting points of triglycerides containing fatty acids, as follows:
I. Palmitic, palmitic, stearic
II. Oleic, stearic, palmitic
III. Oleic, linoleic, oleic

A

ANSWER: III < II < I

54
Q

A falling raindrop initially has no dissolved oxygen. The saturation concentration for oxygen in the drop of water is 9.20 mg · L−1. If, after falling for 2 s, the droplet has an oxygen concentration of 3.20 mg · L−1, how long must the droplet fall (from the start of the fall) to achieve a concentration of 8.20 mg · L−1? Assume that the rate of oxygen exchange is first-order.

A

10.4 s

55
Q

The concentration of carbon dioxide in water at 200C is determined to be 1x10-5 M. The Henry’s constant for carbon dioxide dissolution in water is 3.91x10-2 M/atm at 200C. What is the partial pressure of the CO2 in the air?

A

2.56x10-4

56
Q

You are working in a site where a leaking underground storage tank has contaminated the soil and groundwater was analyzed and the concentrations of benzene and methyl tertiary butyl ether (MTBE) were found to be 45 and 500 micro grams per liter, respectively. At the soil temperature (100C) the dimensionless Henry’s constants, H for benzene and MTBE are 0.09 and 0.01, respectively. Calculate the soil vapor concentrations of both chemical compounds.

A

Benzene = 0.36 micro g/L and MTBE = 5 micro g/L

57
Q

Radioactive solid nuclear wastes are disposed off by
A. high temperature incineration
B. pyrolysis
C. pathological incineration
D. underground burial in concrete containers

A

D. underground burial in concrete containers

58
Q

A contaminated soil is to be excavated and treated in a completely mixed aerated lagoon at a Superfund site. To determine the time it will take to treat the contaminated soil, a laboratory completely mixed batch reactor is used to gather the following data. Determine the time to achieve 99% reduction in the original concentration.

A

92 days

59
Q

Calculate the theoretical oxygen demand of glutamic acid. Assume the concentration of glutamic acid is 0.1 mM.

A

ANSWER: 21 mg/L

60
Q

Compute the theoretical NBOD of a wastewater containing 30 mg/L of ammonia as nitrogen. If the wastewater analysis was reported as 30 mg/L of ammonia (NH3), what would the theoretical NBOD be?

A

137 mg/L and 113 mg/L

61
Q

A sample of municipal sewage is diluted to 1% by volume prior to running a BOD5 analysis. After 5 days the oxygen consumption is determined to be 2.00 mg/L. What is the BOD5 of the sewage?

A

ANSWER: 200 mg/L

62
Q

If the BOD of a municipal wastewater at the end of 7 days and 250C is 60.0 mg/L and the ultimate BOD is 85.0 mg/L, what is the rate constant at 160C?
A. 0.08/d C. 0.11/d
B. 0.22/d D. 0.30/d

A

ANSWER: A. 0.08/d

63
Q

The following data are provided to you:
Seeded wastewater:
Initial DO = 8.6 mg/L Final DO (after 5 d) = 2.1 mg/L
Volume of wastewater = 2.5 mL
Total volume in BOD bottle = 300 mL
Seeded dilution water:
Initial DO = 8.6 mg/L Final DO (after 5 d) = 7.3 mg/L
Temperature = 200C
Calculate the BOD of the sample in mg/L.
A. 598 C. 760
B. 625 D. 832

A

625

64
Q

A large stream has a reoxygenation constant of 0.4/day and a velocity of 0.85 m/s. At the point at which an organic pollutant is discharged, it is saturated with oxygen at 10 mg/L. Below the outfall the ultimate demand for oxygen is found to be 20 mg/L, and the deoxygenation constant is 0.2/day. What is the dissolved oxygen 48.3 km downstream?

A

7.8 mg/L

65
Q

The initial ultimate BOD after mixing of the Bergelmir River is 12.0 mg/L. The DO in the Bergelmir River after the wastewater and river have mixed is at saturation. The river temperature is 10◦C. At 10◦C, the deoxygenation rate constant (kd) is 0.30/day, and the reaeration rate constant (kr) is 0.40/day. Determine the critical DO.

A

7.53 mg/L

66
Q

A stream flowing with a velocity of 2 mph contains no BOD, but has an oxygen deficit of 6 mg/L. Ten miles downstream this deficit has been reduced to 4 mg/L through adsorption from the atmosphere. The stream conditions are uniform throughout its length. Assuming the rate of aeration is proportional to the deficit, what would be the deficit 35 miles downstream from the original point?

A

1.45 mg/L

67
Q

Calculate the exact alkalinity of a water containing 120 mg/L of bicarbonate ion and 15 mg/L of carbonate ion if the pH is 9.43.
A. 124 mg/L as CaCO3
B. 229 mg/L as CaCO3
C. 330 mg/L as CaCO3
D. 452 mg/L as CaCO3

A

A. 124 mg/L as CaCO3

68
Q

A water contains 100.0 mg · L−1 CO2−3 and 75.0 mg · L−1 HCO−3 at a pH of 10 (T = 25◦C). Calculate the exact alkalinity. Approximate the alkalinity by ignoring the appropriate chemical species.

A

ANSWER: 233 mg/L as CaCO3

69
Q

Given the following data for Marikina River and Pasig River, determine the best combination of plant and location to conserve the environment.

A

ANSWER: Plant B in Marikina River
Low D, High DO

70
Q

If a 1.0 m3 · s−1 flow water treatment plant uses ten sedimentation basins with an overflow rate of 15 m3 · day−1 · m−2, what should be the surface area (m2) of each tank?

A

ANSWER: 576 m2

71
Q

Determine the following temperature profiles (Z in m vs T in degC), determine whether the atmosphere is unstable, neutral or stable.
A) 2, -3.05 and 318, -6.21
B) 10, 6 and 202, 3.09
C) 18, 14.03 and 286, 16.71
A. stable, stable, unstable
B. neutral, stable, unstable
C. neutral, unstable, stable
D. stable, unstable, neutral

A

C. neutral, unstable, stable

72
Q

A power plant in Benguet is burning coal on a cold clear January at 8:00 am with a wind speed of 2.6 meters/second measured at an elevation of 31 meters and an inversion layer with its base founded at a height of 695 meters. The effective height of the stack is 31 meters. Calculate the distance downward wt which the plume released will reach the inversion layer and start to mix downward.

A

ANSWER: 5.8 km

73
Q

A landfill with a gas collection system is in operation and serves a population of 200,000. MSW is generated at a rate of 1.95 kg · (capita)−1 · day−1. Gas is produced at an annual rate of 6.2 L · kg−1 of MSW delivered to the landfill. The gas contains 55% methane. Gas recovery is 15% of that generated. The heat content of the landfill gas is approximately 17,000 kJ · m−3 (a value lower than the theoretical value because of dilution of the methane with air during recovery). The landfill company and a developer have proposed to build a subdivision in the vicinity of the landfill and pipe the methane generated to the homes to be used for heating. The homes are estimated to use an average of 110 × 106 kJ of heat energy each year. Peak usage during winter is 1.5 times the average usage. How many homes can be built in the subdivision?

A

ANSWER: 7 homes

74
Q

Determine the area required for anew landfill in Batangas province with projected life of 30 years for a population of 250000 people generating 2.10 kg per capita per day. The density of the compacted waste is 472 kilograms per cubic meter. The height of the landfill should not exceed 16 meters.

A

78 ha

75
Q

The Tanay Rizal Stone Works employs six workers who produce uncompacted waste from the products formed for building decors. If the density of the uncompacted waste is 480 kilograms per cubic meters, determine the annual volume of solid waste produced by the factory assuming a waste generation volume rate of one kilogram per capita per day.

A

4.56

76
Q

The Malayan landfill about 100 kilometers from Kuala Lumpur serves a population of 562,400 people generating MSW at a rate of 1.90 kilograms per capita per day. The capacity of the landfill is 11.3x106 cubic meters. In 2015, 63% of the landfill was being used. The ratio of cover to compacted fill is 1.95. Calculate the remaining projected life for the landfill. Assume the density of the compacted waste to be 492 kilograms per cubic meters.

A

2.76 years

77
Q

A town of 20,000 in Laguna generates 0.96 kg/(capita)-day of MSW. A town of the same size in the Makati City in Metro Manila generates 1.9 kg/(capita)-day of MSW.
How much MSW is generated in each town?
How many trucks would be needed to collect the waste twice weekly? The trucks each have a capacity of 4.5 MT and operate 5 days per week. Assume that the trucks average two loads per day at 75% capacity. Calculate the number and volume of MSW in tons that enter the landfill

A

ANSWER: 19100 kg/d and 39000 kg/d, 4 and 8 trucks, 58 m3/d 105 m3/d

78
Q

A municipal landfill has available space of 16.2 ha at an average depth of 10 m. Seven hundred sixty-five (765) cubic meter per day of solid waste is dumped at the site 5 days a week. This waste is compacted to twice its delivered density. Draw a mass-balance diagram and estimate the expected life of the landfill in years.

A

16 years

79
Q

A deer eats 25 kg of herbaceous material per day. The herbaceous matter is approximately 20% dry matter (DM) and has an energy content of 10 MJ/(kg DM). Of the total energy ingested per day, 25% is excreted as undigested material. Of the 75% that is digested, 80% is lost to metabolic waste products and heat. The remaining 20% is converted to body tissue. Calculate the percentage of energy consumed that is converted to body tissue.
A. 15% C. 19%
B. 20% D. 24%

A

A. 15%

80
Q

If one gallon of blood was added in three gallons of water, and one ounce of that dilution was added to 9 ounces of water, what is the final dilution when 7mL of that dilution was added to 563 mL of water?

A

ANSWER: 3.11x10-4

81
Q

In a gas mixture containing 100mg/L H2S gas at 25 ̊C and 1atm, determine the partial pressure exerted by the gas.

A

0.071

82
Q

When formic acid is 4.6% ionized in 0.105M of aqueous solution at room temperature, determine the ionization constant of the acid. If the solution containing 0.25N of 25mL acid is diluted to 202mL and titrated with 0.35 NaOH, calculate the pH value and the concentration of the hydrogen ion at the equivolume part.
A. 2.2x10-4; 8.06; 8.7x10-9
B. 1.8x10-5; 9.1; 7.2x10-10
C. 4.1x10-4; 7.21; 6.4x10-10
D. 3.4x10-4; 6.32; 5.23x10-11

A

A. 2.2x10-4; 8.06; 8.7x10-9

83
Q

Analyze and calculate the percentage of nickel in a 1.201g sample of nickel ore which was analyzed by the volumetric method. A solution of 48mL containing 1.4x10-2 g of KCN/mL and the excess cyanide required half a milliliter of silver nitrate solution with 1.25x10-2 g AgNO3 per milliliter.

A

12.5%

84
Q

You are working in a site where a leaking underground storage tank has contaminated the soil and groundwater was analyzed and the concentrations of benzene and methyl tertiary butyl ether (MTBE) were found to be 45 and 500 micro grams per liter, respectively. At the soil temperature (100C) the dimensionless Henry’s constants, H for benzene and MTBE are 0.09 and 0.01, respectively. Calculate the soil vapor concentrations of both chemical compounds.

A

ANSWER: Benzene = 0.36 micro g/L and MTBE = 5 micro g/L

85
Q

A solution of cation gives a crimson red flame. This flame test is a confirmatory test for:
a. Sr2+ c. Mn2+
b. K+ d. Ca2+

A

a. Sr2+

86
Q

What is the color of nickel chloride?
a. white c. red
b. blue d. yellow

A

d. yellow

87
Q

Substances whose solutions change color due to changes in pH.

A

Indicator

88
Q

Determine the pH of 0.21 M solution of sodium benzoate in water at room temperature.

A

8.74

89
Q

An adiabatic process is one in which the system under investigation is thermally isolated so that there is no exchange of heat with the surroundings. Thus, the work done on a closed system in an adiabatic process is _____.
A. Equal to zero
B. Not equal to the exchange of heat with surroundings
C. Equal to the increase in internal energy of the system
D. Not equal to the increase in internal energy of the system

A

C. Equal to the increase in internal energy of the system

90
Q

State Le Chatelier’s Principle.
A. Le Chatelier’s principle states that when a stress is placed on a system in equilibrium, the system tends to change in a way that relieves the stress.
B. All of these
C. Examples of the application of Le Chatelier’s principle are blowing your breath through a straw and dissolving alka seltzer tablet in a glass of water.
D. Le Chatelier’s principle explains both the formation and decomposition of acids, where anything that might act to increase the concentration of an acid would produce an increase in the other components so as to keep the numerical

A

A. Le Chatelier’s principle states that when a stress is placed on a system in equilibrium, the system tends to change in a way that relieves the stress.
B. All of these

91
Q

What is the Clapeyron Equation?
A. Any of these
B. It postulates that the colligative properties, freezing point depression, boiling point elevation, osmotic pressure, and vapor pressures are all dependent on the number f particles in the solution and any change thereof is described.
C. It postulates that if two components systems consisting of solid and liquid phases are miscible in the liquid state and immiscible in the solid state, only the pure solid systems will separate out on cooling solutions.
D. It postulates that if the temperature and pressure are both change in such a way as to keep the chemical potentials of two phases equal to each other, the rates of change are given by the equation.

A

D. It postulates that if the temperature and pressure are both change in such a way as to keep the chemical potentials of two phases equal to each other, the rates of change are given by the equation.

92
Q

In a standard chemical reaction, rate is governed by the relationship rate=pze-E/RT, where p and z refer to the probability that reacting molecules make a favorable encounter. To increase the probability of reaction, enzymes are employed. Based on the above equation, if E is the activation energy, which is more favorable and why? A lower or hgher E?
A. Lower E so that more molecules possess sufficient energy to react
B. Higher E so that a better nucleophile and electrophile are catalyzed
C. Lower E so that a proton can be donated or stolen for the reactants leading
to better catalysis
D. Higher E so the bonds of the reactants will be strained and provide more power transition state condition

A

C. Lower E so that a proton can be donated or stolen for the reactants leading

93
Q

The coexistence curve where the plot of pressure versus temperature along which the two phases coexist was shown by Clausius- Clapeyron. What did Clausius postulate?
A. The Clapeyron equation was simplified by assuming that the vapor obeys the ideal gas law and by neglecting the molar volume of the liquid VL in comparison with the molar volume of the gas VG
B. The Clausius-Clapeyron equation does not apply to this situation
C. The Clausius-Clapeyron theory is applicable only for vaporization
and sublimation condition
D. Both scientists apply their postulates to linear and curvilinear
representation

A

A. The Clapeyron equation was simplified by assuming that the vapor obeys the ideal gas law and by neglecting the molar volume of the liquid VL in comparison with the molar volume of the gas VG

94
Q

What is the significance of colligative property in physical chemistry?
a. It refers to the freezing point depression, boiling point elevation, osmotic pressure and lowering of the vapor pressure by a nonvolatile solute
b. It refers to the temperature, pressure and energy of fusion of volatile solutes in phase equilibrium
c. It refers to the non-existence of pressure among molecules within the solute
d. It refers to the temperature differentials exhibited by non-volatile solutes in reactions

A

a. It refers to the freezing point depression, boiling point elevation, osmotic pressure and lowering of the vapor pressure by a nonvolatile solute

95
Q

In the collision theory of chemical kinetics, it is suggested that reaction rate is governed by the relationship rate=Pze-E/RT. What can an enzyme do to the activation energy of the reaction E?
A. Enzymes can raise temperature to make the reaction proceed faster
B. None of these
C. Enzymes bind the reactants in close proximity for a longer period
in order to get the reaction energy going
D. Enzymes provide an alternative reaction pathway in lowering the energy level of the reaction

A

D. Enzymes provide an alternative reaction pathway in lowering the
energy level of the reaction

96
Q

What is the theory in two or three dimensional collision to be applied when playing billiard balls and in order to sink the target ball in the corner pocket?
A. The center of the mass theory where the center of the mass of the system moves as all the mass in the system were concentrated at that point, and one of them is initially at rest, and they were in perpendicular direction of the collision
B. Proton-proton elastic collision
C. The component of momentum an isolated system in each of the directions (x, y, z) are conserved independently
D. Where two equal masses undergo a glancing elastic collision

A

D. Where two equal masses undergo a glancing elastic collision

97
Q

When travelling at NLEX at 80mph, a stopped car in front causes you to suddenly skid to stop. What happened to the kinetic energy of the moving car?
A. Some of it were converted to internal energy and
some transferred to the road and surroundings
B. It was transferred to the internal energy of the road
C. All of it transferred to the road and surroundings
D. All of it are still in the car

A

C. All of it transferred to the road and surroundings

98
Q

Using the van der Waals, derive the equation for (dH/dP)T for van der Waals gas and estimate (dH/dP)T for CO2 (g) in J/barmol when the temperature is at 300 K given the data a = 3.64 L2/bar/mol/mol and b = 0.042 L/mol.

A

b-2a/RT; -25

99
Q

Using data given below, calcukate the DO concentration just mixing
Oz Babbling Run
Flow 0.36 4.8
Ultimate BOD 27 1.35
DO 0.9 8.5

A

8

PROB SOLVING PBE (11 decks)

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