Day 1 - ARC ENVI Flashcards

Question 1

Q

Balance this equation which reported the chemical reaction occuring in the aeration of water for drinking purposes:

Fe (HCO3) 2 + O2 + H2O = Fe (OH)3 + CO2

a. 4, 1, 2, 4, 8
b. 3, 2, 2, 3, 6
c. 1, 1, 2, 1, 4
d. 2, 2, 4, 2, 4

Question 2

Q

Balance the following oxidation, reduction reaction equations:

KMnO4 + FeSO4 + H2SO4 + Fe2(SO4)3 + K2SO4 +MnSO4 + H2O

a. 2, 10, 8, 5, 1, 2, 8
b. 5, 2, 10, 1, 5, 2, 10
c. 3, 5, 8, 1, 1, 2, 5
d. 4, 1, 8, 2, 8, 1, 10

Question 3

Q

The lead acid battery offers a great advantage over the common flashlight battery. Balance the equation:

PbSO4 + H2O = Pb + PbO2 + H2SO4

a. 2, 2, 1, 1, 2
b. 6, 3, 9, 9
c. 1, 4, 2, 2, 6
d. 4, 4, 2, 8

Question 4

Q

Balance the equation when methanol is used as formula one fuel for racing cars, assuming the complete combustion of air.

a. 1, 2, 4, 3
b. 4, 3, 1, 2
c. 2, 3, 2, 4
d. 3, 1, 3, 1

Question 5

Q

In alkaline chlorination, the indicative reactions are shown below. Balance the equations:

NaCN + NaOH = C12NaCNO + NaCl + H2O
NaCNO + NaOH = Cl2NaCl + CO2 + NaHCO3 + H2O

a. 1, 2, 1, 1, 2, 1 and 2, 5, 3, 6, 1, 1, 1, 2
b. 2, 1, 1, 1, 1, 2 and 3, 5, 2, 1, 6, 1, 1, 4
c. 1, 1, 1, 1, 1, 1 and 1, 2, 3, 3, 1, 1, 1, 2
d. 1, 1, 2, 2, 2, 1 and 3, 2, 5, 5, 6, 1, 1, 1

Question 6

Q

Balance the following equations:

Al (s) + HCl (aq) = AlCl3 (s) + H2 (g)
C2H2 (g) + O2 (g) = CO2 (g) + H2O (l)

a. 2, 6, 2, 3; 2, 5, 4, 2
b. 5, 7, 2, 2; 3, 6, 6, 4
c. 6, 3, 3, 3; 1, 4, 2, 3
d. 4, 8, 2, 4; 4,10, 6, 4

Question 7

Q

What is the molecular weight in amu (g/mol) of 11-tetradecenyl acetate? (C16H30O2)

a. 382.4
b. 25.4
c. 196.2
d. 505.8

Question 8

Q

What is the empirical formula and chemical name of an ionic compound used as food additive and dietary supplement if it contains 22.11% manganese, 1.6% hydrogen, 24.92% phosphorus, and 51.42% oxygen?
a. MnHPO3, manganese phosphate
b. Mn2(HPO)4, dimanganese dihydrogen phosphate
c. MnH4P2O8, manganese hydrogen phosphate
d. Mn3(H2PO4)1, tri manganese hydrophosphate

Question 9

Q

What is the formula of the ionic compound that is forced between the following ions: lithium and chloride ions; lithium and oxide ions; lithium and nitride ions?
a. Li3Cl, Li3O2. LiN
b. Li4Cl2, Li3O3, LiN3N3
c. Li2Cl2, LiO2, LN3
d. LiCl, Li2O, Li3N

Question 10

Q

What is the organic molecular formula for a certain organic polychlorinated biphenyl similar to chlorinatie insecticides if the compound contains 3.95% Carbon, 1.313% hydrogen, and 58.95% chlorine with a molecular mass of 360.89?
a. C14H8Cl14
b. C6H2Cl13
c. C10H8Cl12
d. C12H6Cl16

Question 11

Q

Determine the oxidation number of chromium in CrF6 3+
a. 2
b. 3
c. 5
d. 6

Question 12

Q

Estimate the energy emitted per photon as well as the quantity of photons emitted per second from a one hundred watt yellow light bulb with y = 500 n, and a one kilowatt microwave source with y = cm emitting 1.99 x 10-19 J per photon and 5.03 x 10^25 photons/sec

a. 3.6 x 10-19 J and 2.77 x 10^20 photons/sec
b. 2.62 x 10-18 J and 3.11 x 10^21 photons/sec
c. 3.91 x 10-20 J and 4.22 x 10^19 photons/sec
d. 4.11 x 10-20 J and 1.67 x 10^20 photons/sec

Question 13

Q

The two Br isotopes 79 Br and 81 Br, each has a natural abundance of about 50%. Determine what is the likely molecular weight of Br2.

a. 162 amu
b. 158 amu
c. 160 amu
d. All are equally like.

Question 14

Q

Determine the mass of 2.5x10^21 Pb atoms

a. 1.252 g
b. 5.00 g
c. 5.00 g
d. 0.87 g

Question 15

Q

Determine the gram molecular weights and equivalent weights of the following: MgCO3; CO2; K2HPO4 and NaNO3. Make the appropriate assumptions.

a. 47.8/51.2; 66.4/71.1; 48.5/35; 67.5/46
b. 52.2/65; 134/36; 88/125; 120/55
c. 84.4/42.3; 44.2/22.3; 175/88; 85.2/85.3
d. 86.2/46; 48.1/51.1; 120/101; 96.3/102

Question 16

Q

The element that is in Group 14 and the fourth period is:
a. Germanium
b. Gallium
c. Iron
d. Manganese

Question 17

Q

Give the technical names of Sc3+, Ti2+, and Sr2+
a. Transition metal ions
b. Scandium 3 plus ion; Titanium 2 plus ion; Strontium 2 plus
c. Scandium (III) ion; Titanium (II) ion; Strontium (II) ion
d. Scandium 44/31 ion; TItanium 47/22 ion; Strontium 97/38 ion

Question 18

Q

Calculate how much ten milligrams of iodine 131/53 will be found in the body of a patient after 32 days (the half-life of iodine 131/53 in 8 days)

a. 0.25 mg
b. 5 mg
c. 0.625 mg
d. 1.25 mg

Question 19

Q

Determine the number of neutrons of the radioactive isotope C14

a. 14
b. 6
c. 8
d. 12

Question 20

Q

Determine how many milligrams of rubidium-84 remains after 99 days from a ten mg sample. The half-life is 33 days.
a. 2.5 mg
b. 5 mg
c. 0.10 mg
d. 1.25 mg

Question 21

Q

An accident occured in the Bataan nuclear powerplant when it was being commissioned 30 years ago, 48.01 grams of tritium was released. If the half-life of tritium is 12.3 years, what was the mass of tritium left afer the 12.3 years and at the end of 49 years.

a. 18.6, 1.6 mg
b. 31.1, 3.6 mg
c. 36.3, 4.1 mg
d. 24.0, 3.0 mg

Question 22

Q

Determine the decay product of americium 241 and the percentage remaining of the original americium after one thousand years. It is given that americium 241 has a half life of approximately 432 years is known to be an alpha emitter.

a. Neptunium 237; 25%
b. Berkelium 246; 85%
c. Tritium6; 65%
d. Bismuth 209; 45%

Question 23

Q

Determine the age of the mineral sample which contains 50.05 mg of 238 Uranium and 14.05 mg of 206 lead. Assume half life for the process of 238 U and 206 Pb at 4.52 x 10^9 years.

a. K = 1.5 x 10-10 per year; 75.2 mg 238 U; 2.2x10^9 years old
b. K = 1.8 x 10-9 per year; 66.2 mg 238 U; 1.8 x10^9 years old
c. K = 0.9x10-8 per year; 56.1 mg 238 U; 1.3x10^9 years old
d. K = 2.10x10-10 per year; 87.1 mg 238 U; 2.8x10^9 years old

Question 24

Q

If aperson breathes 100 breathes per minute and is aged 75, how many breathes will he/she have during his lifespan
a. 3.942x10^9
b. 5.256x10^6
c. 4.923x10-6
d. 6.044x10-5

Question 25

Q

To which subatomic particle does each statement refer to
i) has a positive chart
ii) is found outside of nucleus
iii) has smallest mass
iv) has negative charge

a. proton, electron, electron, electron
b. proton, electron, proton, electron
c. electron, electron, proton, proton
d. electron, proton, electron, electron, proton

Question 26

Q

Determine the boiling point and freezing points, vapor pressure at 23degC of pure benzene, and a solution of benzene in 1.202 gms of naphthalene in 25.63 g benzene; the molality and osmotic pressure of the solution.

a. 75 deg C, 1.6 deg C; 82.1 mmHg; 0.247 M, 6.3 atm
b. 191 deg C, 5.0 deg C; 102 mmHg; 0.432 M, 9.0 atm
c. none of these
d. 81 deg C, 3.6 deg C; 83.6 mmHg, 0.32 M, 7.78 atm

Question 27

Q

A metal plating firm is installing a precipitation system to remove Zinc. It is the plan to use a pH meter to cntrol the feed of hydroxide solution to the mixing tank. What pH should the controller e set at to achieve a zinc effluent concentration of 0.81 mg per liter?

Given: Ksp of Zn(OH)2 is 7.7x10-17
Zn2+ 2OH- = Zn(OH)2
Ksp = [Zn2+] [OH-]^2

a. pH = 8.38
b. pH = 6.34
c. pH = 7.82
d. pH = 9.01

Question 28

Q

Define a salt in terms of acids and bases

a. A salt is a compound that follows Le Chatelier principle in reactions with other compounds
b. All of these
c. A salt is a compound formed when the nucleus of a hydrogen atom enters a quantity of water
d. A salt is a compound (other than water) produced by the reaction of acid and a base

Question 29

Q

If 5 grams of methane gas is burned at constant pressure, determine the heat released in kJ. If the change in entropy that accompanied the reaction is -890 kJ.
a. -360 K
b. -250.01 K
c. -278.12 K
d. -192.00 K

Question 30

Q

If one mole of an ideal gas is kept at 0degC, during an expansion from 3L to 10L, how much work is done as the gas during the expansion?

a. -2.2x10^4 J
b. -5x10^3 J
c. -2.7x10^3 J
d. -7.8x10^5 J

Question 31

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 = 3.64 L^2 bar/mol/moll and b= 0.042 L/mol

a. b-2a/RT; -25
b. 2b-a/RT; +60
c. a+b/RT; +45
d. a+2b/RT; +30

Question 32

Q

If the temperature at the beginnning of the compression process of an air standard otto cycle is 27degC at a compression ratio of 8, pressure at 101.1 kPa and cylinder volume of 566.2 cm^2, determine the (1) thermal efficiency; (2) the mean effective pressure, using the PG model for air, Maximum temperature during the cycle is 1727 degC, (3) if the IG model was used, find the answers.
a. 56.5%, 710.2 kPa; 51%, 806 kPa
b. 43.2%, 620.5 kPa; 61%, 906 kPa
c. 58.5%, 750.2 kPa; 71%, 760 kPa
d. 65.8%, 810.6 kPa; 81%, 660 kPa

Question 33

Q

Determine which of the following occurrences tells us what happens when Le Chatelier’s principle is applied whether these are TRUE or FALSE
i) The addition of a component cause the equilibrium to shift to the opposite side.
ii) The removal of the component causes the equilibrium to the side from which the component is removed
iii) Increasing the temperature drives an exothermic equilibrium to the side of the reactants, an endothermic equilibrium to the side of the product
iv) The additionition of a catalyst has NO effect on the position of the equilibrium

a. T; F; T; F
b. T; T; T; T
c. F; T; F; T
d. F; F; F; F

Question 34

Q

When a can of soda is opened and CO2 is released to the atmosphere, what is the resultant pH of the soda?
a. Decreases
b. Increases
c. The same
d. All these

Question 35

Q

In the metal plating in Cagayan de Oro and Iligan, the waste contains 20 mg/L of Cu2+. It was decided that no precipitate most of copper in the water, Ca(OH)2 will be used, until only 0.5 mg/L of Cu remains. Estimate the hydroxide concentration in moles/L needed to accomplish this.

a. 3.2x10-5 mol/L
b. 4.17x10-4 mol/L
c. 1.6x10-7 mol/L
d. 2.1 x10-6 mol/L

Question 36

Q

A certain gas confined in a cylinder by a piston, where the initial pressure in the system is 7 bar and the volume is 0.11 cubic meter. The piston is held in place by latches and the apparatus is in vacuum. Determine the change in energy when the latches are removed suddenly and the gas expands to double its initial volume and the piston strikes the latches at the end of the process.
a. 11.54 kJ
b. 0.77 kJ
c. 0.59 kJ
d. no change

Question 37

Q

If the entropy of a system decreases, the entropy of its surrounding
a. must always increase
b. must always decrease
c. may increase or decrease
d. not enough information to answer the question

Question 38

Q

For a particular chemical reaction, delta H is positive and delta S is negative. Which of the following statements about the spontaneoity of the reaction under standard conditions is TRUE?

a. The reaction will be spontaneous only if the magnitude of delta H is large enough to cover the unfavorable entropy change.
b. The reaction will be spontaneous only if the magnitude of delta S is large enough to overcome the unfavorable enthalpy change.
c. The reaction will be spontaneous regardless of the magnitudes of delta H and delta S.
d. The reaction cannot be spontaneous

Question 39

Q

Equal number of moles of helium, argon, and neon are placed in a glass vessel at room temperature. If the vessel has a pinhole-sized leak, which of the following will be true regarding the relative values of the partial pressure of the gases remaining in the vessel after some of the gas mixture has effused?

a. P(He) > P(Ne) > P(Ar)
b. P(Ne) > P(Ar) > P(He)
c. P(Ar) > P(Ne) > P(He)
d. P(Ne) = P(He) = P(Ar)

Question 40

Q

Hydrogen gas has a molecular collision diameter of 0.258 nm. Calculate the mean free path of hydrogen at 298.15 K and 133.32 Pa.

a. 0.3 mm
b. 0.1 mm
c. 0.4 mm
d. 0.2 mm

Question 41

Q

In an open beaker at 25degC and 1 atm pressure, 100 g of zinc are caused to react with dilute sulfuric acid. What would be the work done if the reaction took place in a sealed vessel?
a. 0 kJ
b. -3.8 kJ
c. -5.5 kJ
d. -8.6 kJ

Question 42

Q

Given the following heat of reactions:

C3H6(g) + 9/2 O2(g) -> 3 CO2 (g) + 3 H2O (l)

delta H = -2091.2 kJ/mol

Cgraphite + O2 (g) -> CO2 (g)

delta H = -393.51 kJ/mol

H2(g) + 1/2 O2 (g) -> H2O (l)

delta H = -285.83 kJ/mol

Calculate the standard enthalpy of formation, delta Hf of gaseous cyclopropane,

3 Cgraphite + 3H2 (g) -> C3H6(g)

a. 39.7 kJ/mol
b. 22.5 kJ/mol
c. 53.2 kJ/mol
d. 48.1 kJ/mol

Question 43

Q

Which of the acid combination is the dominant composition of acid rain?

a. nitric acid and carbonic acid
b. nitric acid and sulfuric acid
c. carbonic acid and sulfuric acid
d. none of the above

Question 44

Q

Radioactive solid nuclear wastes are disposed off by:

a. high temeperature incineration
b. pyrolysis
c. pathological incineration
d. undergoround burial in concrete containers

Question 45

Q

Amount of oxygen needed to chemically oxidize the organic solids. It is important that organic wastes be removed to protect the receiving body of water into which the wastewaster plant is discharging

a. COD
b. DO
c. BOD
d. ThOD

Question 46

Q

Which of the following plays a part in the nitrogen cycle?

a. evaporation
b. lightning
c. snow
d. rain

Question 47

Q

In the determination of BOD, the reaction takes place in the dark because

a. The microorganisms are sensivie to light
b. Oxygen is sensitive to light
c. The reaction is enhanced in the dark
d. Algae may be present and produce oxygen

Question 48

Q

The company you work for plans to release a waste stream containing 7 mg/L of benzaldehyde. Calculate the theoretical oxygen demand of this waste stream in mg/L

a. 17
b. 29
c. 22
d. 30

Question 49

Q

Determine the theoretical oxygen demand of 100 ppm of glutamic acid

a. 44 pm
b. 98 ppm
c. 130 ppm
d. 141 ppm

Question 50

Q

What sample size (in percent) is required for a BOD5 of 350 mg/L if the oxygen consumed is to be limited to 6 mg/L

a. 2.9%
b. 3.3%
c. 1.7%
d. 4.8%

Question 51

Q

What is the required volume of the sample?
a. 5.14 ml
b. 4.09 ml
c. 6.28 ml
d. 3.33 ml

Question 52

Q

The BOD rate constant is 0.223/day for a municipal wastewater. The BOD5 was measured to 250 mg/L. What is the ultimate BOD?

a. 289 mg/L
b. 404 mg/L
c. 195 mg/L
d. 363 mg/L

Question 53

Q

If the BOD of a municipal wastewater at the end of 7 days is 60 mg/L and the ultimate BOD is 85 mg/L, what is the rate constant?

a. 0.22/d
b. 0.25/d
c. 0.17/d
d. 0.19/d

Question 54

Q

Assuming that the data in problem 53 were taken at 25degC, compute the rate constant at 16degC

a. 0.08/d
b. 0.22/d
c. 0.11/d
d. 0.30/d

Question 55

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 water = 300 mL

Seeded dilution water

Initial DO = 8.6 mg/L
Final DO (after 5 d) = 7.3 mg/L
Volume of seeded dilution water= 300 mL
Temperature = 20degC

Calculate the BOD of sample in mg/L

a. 598
b. 625
c. 760
d. 832

Question 56

Q

The Waramurungundi tannery with a wastewater flow of 0.011 m3/s and a BOD5 of 590 mg/L and discharges into the Djanggawul Creek. The creek has a 10-year, 7-day low flow of 1.7 m3/s. Upstream of the of the Waramurungundi tannery, the BOD5 of the creek is 0.6 mg/L. The BOD rate constants (k) are 0.115/d for the Waramurungundi tannery and 3.7/d for the creek. Calculate the initial ultimate BOD after mixing.

a. 9.3 mg/L
b. 8.8 mg/L
c. 7.1 mg/L
d. 6.0 mg/L

Question 57

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

Question 58

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. 95 hectares
b. 65 hectares
c. 78 hectares
d. 88 hectares

Question 59

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. 3.22 cubic meters
b. 8.01 cubic meters
c. 5.56 cubic meters
d. 4.65 cubic meters

Question 60

Q

A falling raindrop initially has no dissolved oxygen. The saturation concentration for oxygen in the drop of water is 9.20 mg/L. If after falling for 2 s the droplet has an oxygen concentration of 3.2 mg/L, how long must the droplet fall (from the start of the fall) to achieve a concentration of 8.2 mg/L. Assume the rate of oxygen exchange is first order.

a. 8.8 s
b. 15.1 s
c. 6.2 s
d. 10.4 s

Question 61

Q

Determine the following temperature profiles (Z in m vs T in deg C), determine whether the atmosphere is unstable, neutral, or stable.

i) 2, -3.05 and 318, -6/21;
ii) 10, 6 and 202, 309;
iii) 18, 14.03 and 286, 16.71

a. stable, stable, unstable
b. neutral, unstable, stable
c. neutral, stable, unstable
d. stable, unstable, neutral

Question 62

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 micrograms per liter, respectively. At the soil temperature (10degC) 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 = 0.44 micro g per L, MTBE = 2 micro g per L
b. Benzene = 0.36 micro g per L, MTBE = 5 micro g per L
c. Benzene = 0.51 micro g per L, MTBE = 9 micro g per L
d. Benzene = 0.60 micro g per L, MTBE = 3 micro g per L

Question 63

Q

Calculate the volumetric flow rate of leachate through a compacted clay liner if the area of the landfill is 15 ha and the liner thickness is 1 m. The hydraulic conductivity is 7.5x10-10 m/s. Assume that the head of water is 0.6 m.

a. 5.98 x10-5 m3/s
b. 1.2 x 10-5 m3/s
c. 3.33 x10-5 m3/s
d. 6.75 x10-5 m3/s

Question 64

Q

A municipal landfill has available space of 16.2 ha at an average depth of 10 m. Seven hundred sixty five (765) m3 of solid waste is dumped at the site 5 days a week. This week is compacted to twice its delivered density. Draw a mass-balance diagram and estimate the expected life of the landfill in years.

a. 16
b. 13
c. 22
d. 25

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Day 1 - ARC ENVI Flashcards

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