Question: The International Humic Substances Society supplies

> A beam of protons traveling at 1.20 km/s enters a uniform magnetic field, traveling perpendicular to the field. The beam exits the magnetic field, leaving the field in a direction perpendicular to its original direction (Fig. E27.24). The beam travels a

> An electron in the beam of a cathode-ray tube is accelerated by a potential difference of 2.00 kV. Then it passes through a region of transverse magnetic field, where it moves in a circular arc with radius 0.180 m. What is the magnitude of the field?

> In a cyclotron, the orbital radius of protons with energy 300 keV is 16.0 cm. You are redesigning the cyclotron to be used instead for alpha particles with energy 300 keV. An alpha particle has charge q = +2e and mass m = 6.64 × 10-27 kg. If the magnetic

> If the battery in Discussion Question Q26.10 is ideal with no internal resistance, what will happen to the brightness of the bulb when S is closed? Why? Discussion Question Q26.10: A real battery, having nonnegligible internal resistance, is connected

> A deuteron (the nucleus of an isotope of hydrogen) has a mass of 3.34 × 10-27 kg and a charge of +e. The deuteron travels in a circular path with a radius of 6.96 mm in a magnetic field with magnitude 2.50 T. (a). Find the speed of the deuteron. (b). F

> Cyclotrons are widely used in nuclear medicine for producing short-lived radioactive isotopes. These cyclotrons typically accelerate H- (the hydride ion, which has one proton and two electrons) to an energy of 5 MeV to 20 MeV. This ion has a mass very cl

> In an experiment with cosmic rays, a vertical beam of particles that have charge of magnitude 3e and mass 12 times the proton mass enters a uniform horizontal magnetic field of 0.250 T and is bent in a semicircle of diameter 95.0 cm, as shown in Fig. E27

> An alpha particle (a He nucleus, containing two protons and two neutrons and having a mass of 6.64 × 10-27 kg) traveling horizontally at 35.6 km/s enters a uniform, vertical, 1.80-T magnetic field. (a). What is the diameter of the path followed by this

> A 150-g ball containing 4.00 × 108 excess electrons is dropped into a 125-m vertical shaft. At the bottom of the shaft, the ball suddenly enters a uniform horizontal magnetic field that has magnitude 0.250 T and direction from east to west. If air resist

> Repeat Exercise 27.15 for the case in which the particle is a proton rather than an electron. Exercise 27.15: An electron at point A in Fig. E27.15 has a speed v0 of 1.41 × 106 m/s. Find Fig. E27.15: A B -10.0 cm-

> The magnetic field

> An open plastic soda bottle with an opening diameter of 2.5 cm is placed on a table. A uniform 1.75-T magnetic field directed upward and oriented 250 from vertical encompasses the bottle. What is the total magnetic flux through the plastic of the soda bo

> A horizontal rectangular surface has dimensions 2.80 cm by 3.20 cm and is in a uniform magnetic field that is directed at an angle of 30.0 above the horizontal. What must the magnitude of the magnetic field be to produce a flux of 3.10 × 10-4 Wb through

> A circular area with a radius of 6.50 cm lies in the xy-plane. What is the magnitude of the magnetic flux through this circle due to a uniform magnetic field B = 0.230 T (a). in the +z-direction; (b). at an angle of 53.1 from the +z-direction; (c). i

> A real battery, having nonnegligible internal resistance, is connected across a light bulb as shown in Fig. Q26.10. When the switch S is closed, what happens to the brightness of the bulb? Why? Fig. Q26.10: S.

> A sheet of copper is placed between the poles of an electromagnet with the magnetic field perpendicular to the sheet. When the sheet is pulled out, a considerable force is required, and the force required increases with speed. Explain. Is a force require

> The following dose-response curve plots the central estimate of the adverse (toxic) response from a series of doses. The dose (i.e., body burden) is plotted on a linear scale and the adverse response is a percentage of the exposed population. Estimate

> The exposure factor Ei,j for the shrew—the US EPA mammalian insectivore test specie—is given by the first expression below. The U.S. EPA wildlife risk model assumes the mammalian insectivore food-source biota Bi,j

> The lung cancer incremental excess lifetime cancer risk ILECR is estimated to be 10−4 resulting from chronic 222Rn(g) exposure at a level of 10 mBq dm−3. The ILECR due to 222Rn(g) exposure in Dane County, Wisconsin can

> An adult Bengali has been drinking water from a tube wells in Lalpur, Nadia District, Bangladesh installed 35 years ago. The well water contains cw = 17 mg • dm−3 total dissolved arsenic. Select an appropriate intake rate and exposure frequency to estim

> The U.S. EPA PBT Profiler (cf. Appendix D, Chapter 8, Surface Chemistry and Adsorption) tabulates selected environmental properties for a broad range of organic compounds. Identify the toxicological end-point on a dose-response curve represented by the

> The U.S. EPA PBT Profiler (cf. Appendix D, Chapter 8, Surface Chemistry and Adsorption) tabulates selected environmental properties for a broad range of organic compounds. Among the tabulated environmental properties are the distribution and half-life of

> Mackay (1982) reports a linear correlation between the bio-concentration factor BCF of organic compounds in fish and the octanol-water partition coefficients Ko−◦/w. The U.S. EPA PBT Profiler (cf. Appendix D, Chapter

> According to a 1992 survey, the drinking water in one-third of Chicago homes had lead levels of 10 ppb. Identify the most sensitive receptor (resident child or resident adult) and calculate the lead average daily dose ADD for a Chicago resident from expo

> In 1996, the U.S. EPA developed a new reference dose for methylmercury CH3Hg+: Rf D = 0.1 mg • kg−1 • day−1. Estimate the amount of fish a 60 kg woman can safely eat each week if the average CH3Hg+ content in the fish consumed is 0.30 ppm.

> An adult consuming 100 micrograms a day of a substance whose steady-state level in the body is later established to be 0.1 mg • kg−1 . Estimate the biological half-life t1/2 for elimination of this substance from the body.

> The following data are the vanadium content of samples of Canadian granite (Ahrens, 1954). Determine the geometric mean and geometric standard deviation from this data set. w(V) Sample mg - kg-1 Sample w(V) mg · kg-1 G-1 21 КВ-1 75 KB-2 43 КВ-3 200

> Estimate the average daily dose ADD of methylmercury CH3Hg+ for an adult who eats 56 g of tuna daily containing 0.2 ppm CH3Hg+. The biological half-life of CH3Hg+ in humans is 70 days.

> A construction worker, age 50 years, ingests soil containing 10 mg kg−1 toluene (CAS Registry Number 108-88-3). The worker’s oral soil ingestion rate is IR = 330 mg day−1. Work-related exposure duration of a typical construction worker in this case is 30

> The two molecular structures below are flavin mononucleotide (FMN) and reduced flavin mononucleotide (FMNH2). Reduced flavin mononucleotide FMNH2 serves as an electron donor in a variety of biochemical reduction- oxidation reactions. Identify which ato

> Given the relation between the Gibbs energy of reaction and the electrochemical potential E of reduction-oxidation reactions, calculate the Standard reduction potential E−◦ for a balanced reduction half-reaction invo

> Given the relation between the Free Energy of reaction and the Electro- chemical Potential for reduction (∆rtt = n F E), calculate the electrochemical potential for the 4,4’-DDT dechlorination half-reaction. The essent

> The molecular structures of 4,4’-DDT (1-chloro-4-[2,2,2-trichloro-1-(4- chlorophenyl) ethyl] benzene, CAS Registry Number 50-29-3) and 4,4’-DDD (1- chloro-4-[2,2-dichloro-1-(4-chlorophenyl)ethyl]benzene, CAS Registry Number 72-54-8) appear below. Determi

> Balance the reduction half-reaction involving the mineral s hausmanite Mn3O4(s) and manganite MnOOH(s).

> Balance the reduction half-reaction involving cystine18 and cysteine19. NH2 но. HO. HS OH NH2 NH2 cystine CAS Registry Number RN 56-89-3 L-cysteine CAS Registry Number RN 52-90-4

> Balance the reduction half-reaction involving the anions S3O 2 –6 and S2O 2 –3.

> The transport of 1,2-dibromoethane (CAS Registry Number 106-93-4) in an aquifer can be estimated using the organic carbon-water partition coefficient measured by any material containing natural organic matter. The adsorption of 1,2-dibromoethane by whole

> Explain the significance of the following geochemical terms: atmophilic, lithophilic, siderophilic, and chalcophilic.

> An Alachlor (CAS Registry Number 15972-60-8) adsorption experiment by a specimen collected from a shallow, organic-rich aquifer near Piketon, Ohio yielded the results listed in the table below. Aquifer porosity was reported to be 37%. (Source: Springer

> An Alachlor (CAS Registry Number 15972-60-8) adsorption experiment by a specimen collected from a shallow, organic-rich aquifer near Piketon, Ohio yielded the results listed in the table below. The organic carbon content of the aquifer is 0.02%. (Sour

> The following data from Clark and McBride (1984) measures Cu 2+ adsorption by imogolite Al2SiO3(OH)4(s) covering a pH range from about 4 to 7. The suspensions, which were prepared with 5 g • dm−3 synthetic imogolite,

> The following data (courtesy of T. Ranatunga and R. W. Taylor, Alabama A & M University) are from an experiment measuring Pb2+ adsorption at pH 4 by kaolinite (Clay Minerals Society specimen: KGa-1). Specimen KGa-1 has a specific surface area of as =

> An experiment measuring SO24 adsorption by a by the aluminum oxide γ– Al2O3(s) yielded the results listed in the following table. Determine whether the adsorption isotherm is best represented by a partitioning isotherm mod

> An adsorption experiment of the chloroacetanilide herbicide Alachlor (CAS Registry Number 15972-60-8) by a shallow organic-rich aquifer near Piketon, Ohio yielded the results listed in the table below. (Source: Springer, A.E. 1994. Characterization and m

> An experiment measuring adsorption of the triazine herbicide Cynazine by a Cheshire soil specimen yielded the results listed in the following table (Xing and Pignatello, 1996). Determine whether the adsorption isotherm is best represented by a partiti

> The International Humic Substances Society IHSS supplies reference specimens to researchers. Using IHSS elemental composition and acidic functional group data, determine the oxygen mole-fraction attributable to carboxyl and phenol groups xtitr in the Sum

> Fungal cell walls contain the polymer chitin (CAS Registry Number 1398- 61-4) with chemical formula (C8H13O5N)n . Verify the formal oxidation state of nitrogen OS(N) = 3 and calculate the mean carbon oxidation state OS(C) for chitin. CH3 HO NH HO 5

> Salibia et al. (2002) reports the following composition of corncob lignin: C9H9.84O3.33(OCH3)0.38. Determine the mean carbon oxidation state OS(C) and carbon reduction ΓC of corncob lignin.

> The Earth’s crust is depleted of certain elements relative to the overall composition of the Solar System. Explain why the following elements (helium, neon, argon, krypton, xenon, silver, gold, platinum) are depleted in the crust.

> The International Humic Substances Society supplies reference samples to researchers (IHSS Products link at the website www.ihss.gatech.edu/). The Chemical Properties menu leads you to data for Elemental Composition. Using the Elemental Composition for t

> Almendros et al. (1991) measured the nitrogen-15 nuclear magnetic resonance NMR spectrum of a compost material containing 8% nitrogen by weight. From the NMR spectrum, Almendros et al. (1991) estimates 8% of the total nitrogen is amine (R – NH2), the for

> The Upper Poplar Creek, a mercury-polluted stream located on the U.S. Department of Energy Oak Ridge reservation, has as dissolve organic carbon content of DOC = 3 mg • dm−3. This aquatic organic matter contains w(C) = 0.525 g • g−1 carbon and w(S) = 6.5

> The International Humic Substances Society supplies reference samples to researchers (IHSS Products link at the website www.ihss.gatech.edu/). The Chemical Properties menu leads you to data for Elemental Composition. Using the Elemental Composition and A

> Table 1.4 in The Chemical Composition of Soils (Helmke, 2000) lists the geometric mean Cu content of U.S. peat soils (Histosols): 193 mg kg−1. The organic matter content of peat soils is essentially 100%. Assume the metal binding capaci

> Table 1.2 in The Chemical Composition of Soils (Helmke, 2000) lists the geometric mean Cu content of world soils: 20 mg kg−1. The soil organic carbon content of the Summit Hill (Christchurch, New Zealand) A-horizon is 4.3% (foc = 0.043

> The International Humic Substances Society IHSS supplies reference specimens to researchers. Using IHSS elemental composition and acidic functional group data, determine the oxygen mole-fraction attributable to carboxyl and phenol groups xtitr in the Pah

> Crandall et al. (1999) published a study of groundwater and river water mixing, listing dissolved salts in groundwater from a number of wells and sinkholes and surface water from the Suwannee and Little Springs rivers in Suwannee County, Florida. The fol

> The Byz2 horizon of the Duke soil series (Fine, mixed, active, thermic Sodic Haplusterts; Harmon County, OK) is 47% smectite clay. The soil dis- plays a “slight effervescence” when treated with dilute hydrochloric acid (in- dicating CaCO3(s)). The Nation

> The Earth’s crust contains thorium and uranium although no stable isotope exists for either element. Explain why these unstable elements are present in the Earth’s crust.

> The Bssyz2 horizon of the Duke soil series (Fine, mixed, active, thermic Sodic Haplusterts; Harmon County, OK; Pedon ID: S2003OK-057-006 DUKE) is 47% smectite clay. The soil displays a “slight effervescence” when treated with dilute hydrochloric acid (in

> The following table lists the chemical analysis of a groundwater specimen from Waukesha, Wisconsin collected in 2003. The electrical (specific) conductivity of the water is EC = 1.05 dS • m−1 and the analytic pH is 8.0. Simulate the chemistry of this sol

> The following table lists the chemical analysis of a groundwater specimen from Waukesha, Wisconsin collected in 2003. The electrical (specific) conductivity of the water is EC = 1.05 dS • m−1 and the analytic pH is 8.0. Calculate the following from the w

> Porębska et. al (2008) studied the effect of acid rain on soils in Poland. The soil chemical properties relevant to acidity of a spodosol near Gubin in western Poland: pH(1 m KCl) = 3.2, CEC7 = 34.2 cmolc kg−1, exchangeable Al3+ = 26.0 cmolc kg−1. Exchan

> Dai et al. (1998) studied the effect of acid rain on soils from the provinces of Hunan and Guangxi in southern China. The soil chemical properties relevant to acidity of the Hongmaochong Inceptisols (surface 0–10 cm) are: pH(1 m KCl) = 3.91, CEC7 = 22.5

> Calculate the amount of CaCO 3(s) required to neutralize the acidity in 829 mm of acid precipitation with an average pH of 4.26 falling on a 1-hectare area.

> The following table lists the chemical analysis of a groundwater sample from Green Bay, Wisconsin. The analytic pH is 7.7. Use Chem EQL to simulate the pH of this groundwater sample. Save both the input file (.txt) and the output file (.xls) for the si

> The Chem EQL database Solid Phase Library (i.e., mineral species formation reactions and equilibrium solubility constants) contains the following entry for the mineral calcite : CaCO3(s). Using the equilibrium reaction and constant above, derive the li

> The Chem EQL Solid Phase Library contains the following entry for the calcium phosphate mineral fluorapatite : Ca10(PO4)6F2(s). Calculate the equilibrium coefficient Kc for this reaction using the Debye-Hückel empirical activity coeffici

> Simulate the 4-phase system consisting of an aqueous solution in solubility equilibrium with the following three minerals: calcite : CaCO3(s), hydroxyapatite : Ca5(PO4)3OH(s), and pyromorphite : Pb5(PO4)3OH(s). Save both the input file (.txt) and the out

> A reactor accident occurred in Chernobyl, Ukraine in 1986 that deposited 55 137

> Simulate total soluble lead (Pb) in a 3-phase system consisting of an aqueous solution in equilibrium with the phosphate minerals hydroxyapatite : Ca5(PO4)3OH(s) and pyromorphite : Pb5(PO4)3OH(s). Save both the input file (.txt) and the output file (.xls

> Simulate troilite : FeS(s) solubility in the pH range: 4 ≤ pH ≤ 9. Save both the input file (.txt) and the output file (.xls) for the simulation.

> Simulate hydroxyapatite : Ca5(PO4)3OH(s) solubility in the pH range: 4 ≤ pH ≤ 9. Save both the input file (.txt) and the output file (.xls) for the simulation. Plot the total solution phosphate concentration and the concentrations of the four (4) most ab

> Simulate the dissolution of gypsum: CaSO4 2 H2O(s), saving both the input matrix file (.txt) and the output file (.xls). Validate the ion activity coefficients γ2± and the gypsum ion activity product IAP using results in the output file.

> Variation 1. Using Chem EQL, simulate the pH of a solution containing c0 = 3.80 10−4 mol dm−3 sulfide S2– and an ionic strength of Ic = 3 10−2 mol dm−3. NOTE: There are two more variations of this exercise. Variation 2. Using Chem EQL, simulate the pH of

> Using the R.I.C.E. table method, calculate the activities of all hydrogen sulfide species for a solution containing c0 = 3.80 10−4 mol dm−3 dihydrogen sulfide H2S(aq). The following reactions give the hydrolysis of dih

> Using the R.I.C.E. table method, calculate the pH of a solution containing c0 = 3.80 • 10−4 mol • dm−3 dihydrogen sulfide H2S(aq). The following reactions give the hydrolysis of dihy

> The standard free energies of formation ∆f tt−◦ (298.15 K) for each component in the fluorapatite : Ca5(PO4)3F(s) solubility reaction appear in the following table (source: CHNOSZ database; Dick, 20

> Install Chem EQL and simulate the chemistry of a 10−5 mol dm−3 phthalic acid solution at pH 5 without setting mode(H+) = free. Save the input matrix file (.txt) and the output file (.xls) and perform a charge-balance validation to determine whether the t

> Install Chem EQL and simulate the chemistry of a 10−5 mol dm−3 phthalic acid solution at pH 5 (cf. Chem EQL Manual, example simulation of 10−3 mol dm−3 acetic acid solution at pH 4). Save the input file4 (.txt) and the output file5 (.xls) and perform a c

> List the half-life of the longest-lived isotope for each element from Po to Th (84 < Z < 90). A complete Table of the Isotopes is available on the Abundances of the Elements (Kaye and Laby Tables of Physical and Chemical Constants, National Physics Labor

> The Chem EQL database Solid Phase Library (i.e., equilibrium solubility constants for mineral species) contains the following entries for the carbonate minerals calcite : CaCO3(s) and dolomite : Ca Mg(CO3)3(s). Figure 8 (cf. Chapter 5, Water Chemistry

> The clay fraction of the Two top soil series (Crook County, Wyoming) is predominantly smectite with a reported cation exchange capacity CEC of nσ /m = 76.4 cmolc • kg−1. An asymmetric Ca2+, K+ cation exchange experiment reports the following results: cK

> Quirk and Schofield (1955) measured Na+, Ca2+ exchange by a vermiculite dominated soil clay fraction collected at Rothamsted Experiment Station (Harpenden, U. K.). The results are listed. Use the least sum-square method to determine the selectivity coeff

> The Bssyz2 horizon of the Duke soil series (Fine, mixed, active, thermic Sodic Haplusterts; Harmon County, OK) is 64.7% clay, has the following chemical properties (NCSS Pedon ID: S2003OK-057-006): pH = 7.7, CEC7 = 24.2 cmolc • kg−1, and a saturated-p

> The Maxfield soil series (Olmsted County, MN) has a cation exchange capacity CEC of nσ +/m = 41.0 cmolc kg−1 balanced by nσ Ca2+ /m = 39.5 cmolc kg−1 of exchangeable Ca2+ and nσ Na+ /m = 1.5 cmolc kg−1 exchangeable Na+. The concentrations of Ca2+ and Na+

> The Ness soil series (Hodgeman County, Kansas) has a cation exchange capacity CEC of n σ +/m = 38.0 cmolc kg−1 balanced by n σ Ca2+ /m = 33.1 mol kg−1 of exchangeable Ca2+ and n Σ Na+ /m = 4.9 mol kg−1 exchangeable Na+. The concentrations of Ca2+ and Na+

> The specific surface area of kaolinite specimens from the clay (< 0.2 µm) fraction is: as ≈ 10 m2 • g−1. The specific surface area of smectite specimens from the clay (< 0.2 µm) fraction is: as ≈ 700 m2 • g−1. Explain the dramatic difference in surface a

> The structure of four layer silicate minerals appear in Figure 3.1. Associate the following with each structure: 1) a specific mineral name, 2) the Jackson chemical weathering stage dominated by each mineral, and 3) whether the mineral is capable of crys

> Apply Pauling&acirc;&#128;&#153;s Radius Ratio rule to determine the preferred coordination of the cation listed in Table 3.1. The ionic radius of oxygen is: rO2&acirc;&#136;&#146; = 0.140 nm. Table 3.1: Abundance Rank Cation Ionic Radius re nm Si

> Describe the importance of plasticity in the field identification of clay content and identify the minerals typically found in the clay-size fraction that exhibit plasticity.

> Figure 2 (cf. Chapter 1, Elemental Abundance) plots the relative abundance of several elements in the solar system, Earth&acirc;&#128;&#153;s crust and Earth&acirc;&#128;&#153;s soil. Explain the factors that determine the relative abundance of the follo

> Identify any crystallographic feature that would permit the solid-state transformation of feldspar minerals into layer silicate minerals.

> Identify the Jackson Weathering Stage where smectite minerals first appear.

> Figure 24 ( cf. Chapter 3, Clay Mineralogy and Chemistry) shows the tension head htension of a 13.5% suspension of Cheto montmorillonite. Compute the actual height of the clay gel above pure water in an osmotic cell equivalent to the osmotic head: hosmot

> Figure 15 ( cf. Chapter 3, Clay Mineralogy and Chemistry) plots the crystalline swelling of a Na+-saturate smectite specimen. Estimate the number of water layers in the interlayer of this smectite at each crystalline swelling state. Figure 15: 2.40

> Compute the osmotic head hosmotic of a CaSO4(aq) solution: cCaSO4 = 1.600 • 10−2 mol • dm−3.

> Estimate the unit cell composition of a Wyoming montmorillonite specimen Volclay (American Colloid Company) using the oxide mass-fraction w(ExOy) data listed in Table 3.4. Table 3.4: Oxide w(E„Oy) Oxide w(E„Oy) 1 1 g•g¯ SiO2 (s) Al2O3(s) Fe2O3(s)

> Describe the special characteristics of Tschermak cation substitution and its significance for cation substitution in layer silicates.

> Clay mineral layer charge influences a variety of chemical and physical properties: swelling behavior, surface area, and the exchangeability of interlayer ions. Explain the relationship between layer charge and the chemical and physical properties listed