Environmental Chemistry

Stanley E. Manahan

Chapter 14 The Geosphere and Geochemistry - all with Video Answers

Educators

Chapter Questions

Problem 1

Of the following, the one that is not a manifestation of desertification is (explain) (A) declining groundwater tables, (B) salinization of topsoil and water, (C) production of deposits of $\mathrm{MnO}_2$ and $\mathrm{Fe}_2 \mathrm{O}_3 \cdot \mathrm{H}_2 \mathrm{O}$ from anoxic processes, (D) reduction of surface waters, (E) unnaturally high soil erosion.

Hast Aggarwal

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01:27

Problem 1

Give two examples of reactions involving manganese and iron compounds that may occur in waterlogged soil.

Lottie Adams

Numerade Educator

01:30

Problem 2

Give an example of how each of the following chemical or biochemical phenomena in soils operates to reduce the harmful nature of pollutants (explain): (A) oxidation-reduction processes, (B) hydrolysis, (C) acid-base reactions, (D) precipitation, (E) sorption, (F) biochemical degradation.

Courtney Burson

Numerade Educator

01:23

Problem 2

What temperature and moisture conditions favor the buildup of organic matter in soil?

Fathima Zahra

Numerade Educator

07:38

Problem 3

"Cat clays" are soils containing a high level of iron pyrite, $\mathrm{FeS}_2$. Hydrogen peroxide, $\mathrm{H}_2 \mathrm{O}_2$, is added to such a soil, producing sulfate as a test for cat clays. Suggest the chemical reaction involved in this test.

Bin Chen

Numerade Educator

00:37

Problem 3

Why do silicates and oxides predominate among the Earth's minerals?

Morgan Thompson

Numerade Educator

02:46

Problem 4

What effect upon soil acidity would result from heavy fertilization with ammonium nitrate accompanied by exposure of the soil to air and the action of oxic bacteria?

Cara Oneal

Numerade Educator

02:09

Problem 4

Give the characteristic that the minerals with the following formulas have in common: $\mathrm{NaCl}, \mathrm{Na}_2 \mathrm{SO}_4$, $\mathrm{CaSO}_4 \cdot 2 \mathrm{H}_2 \mathrm{O}, \mathrm{MgCl}_2 \cdot 6 \mathrm{H}_2 \mathrm{O}, \mathrm{MgSO}_4 \cdot 7 \mathrm{H}_2 \mathrm{O}, \mathrm{KMgClSO}_4 \cdot 1 / 4 \mathrm{H}_2 \mathrm{O}$, and $\mathrm{K}_2 \mathrm{MgCa}_2\left(\mathrm{SO}_4\right)_4 \cdot 2 \mathrm{H}_2 \mathrm{O}$.

Ronald Prasad

Numerade Educator

00:37

Problem 5

How many moles of $\mathrm{H}^{+}$are consumed when $200 \mathrm{~kg}$ of $\mathrm{NaNO}_3$ undergo denitrification in soil?

Matthew Confer

Numerade Educator

01:51

Problem 5

Explain how the following are related: weathering, igneous rock, sedimentary rock, soil.

William Dunkerton

Numerade Educator

Problem 6

Match the following:
a. Metamorphic rock
b. Chemical sedimentary rocks
c. Detrital rock
d. Organic sedimentary rocks
1. Produced by the precipitation or coagulation of dissolved or colloidal weathering products
2. Contain residues of plant and animal remains
3. Formed from action of heat and pressure on sedimentary rock
4. Formed from solid particles eroded from igneous rocks as a consequence of weathering

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01:28

Problem 6

What is the primary mechanism by which organic material in soil exchanges cations?

Rabia Bibi

Numerade Educator

01:40

Problem 7

Where does most flowing water that contains dissolved load originate? Why does it tend to come from this source?

Ma Ednelyn Lim

Numerade Educator

02:40

Problem 7

Prolonged waterlogging of soil does not:
a. Increase $\mathrm{NO}_3^{-}$production
b. Increase $\mathrm{Mn}^{2+}$ concentration
c. Increase $\mathrm{Fe}^{2+}$ concentration
d. Have harmful effects upon most plants
e. Increase production of $\mathrm{NH}_4^{+}$from $\mathrm{NO}_3^{-}$

David Collins

Numerade Educator

01:27

Problem 8

What role might be played by water pollutants in the production of dissolved load and in the precipitation of secondary minerals from it?

Lottie Adams

Numerade Educator

02:09

Problem 8

Of the following phenomena, the one that eventually makes soil more basic is:
a. Removal of metal cations by roots
b. Leaching of soil with $\mathrm{CO}_2$-saturated water
c. Oxidation of soil pyrite
d. Fertilization with $\left(\mathrm{NH}_4\right)_2 \mathrm{SO}_4$
e. Fertilization with $\mathrm{KNO}_3$

Christina Sorrentino

Numerade Educator

00:25

Problem 9

As defined in this chapter, are the ions involved in ion replacement the same as exchangeable cations? If not, why not?

Sam Limsuwannarot

Numerade Educator

00:50

Problem 9

How many metric tons of farm manure are equivalent to $100 \mathrm{~kg}$ of $10-5-10$ fertilizer?

Catherine Lemar

Numerade Educator

03:04

Problem 10

How are the chelating agents that are produced from soil microorganisms involved in soil formation?

Maryam Riaz

Numerade Educator

Problem 10

Speculate regarding how water present in poorly consolidated soil might add to the harm caused by earthquakes.

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01:03

Problem 11

What specific compound is both an animal waste product and a major synthetic fertilizer?

Narayan Hari

Numerade Educator

01:56

Problem 11

In what sense may volcanoes contribute to air pollution? What possible effects may this have on climate?

Wan Deng

Numerade Educator

Problem 12

What happens to the nitrogen/carbon ratio as organic matter degrades in soil?

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05:47

Problem 12

Explain how excessive pumping of groundwater might adversely affect streams, particularly in regard to the flow of small streams.

Danielle Ashley

Numerade Educator

09:15

Problem 13

To prepare a rich potting soil, a greenhouse operator mixed $75 \%$ "normal" soil with $25 \%$ peat. Estimate the CEC in milliequivalents/ $100 \mathrm{~g}$ of the product.

Andrija Isakov

Numerade Educator

01:48

Problem 13

Which three elements are most likely to undergo oxidation as part of chemical weathering process? Give example reactions of each.

Vasu Makani

Numerade Educator

01:36

Problem 14

Explain why plants grown on either excessively acidic or excessively basic soils may suffer from calcium deficiency.

Hailey Ames

Numerade Educator

01:08

Problem 14

Match the following:
a. Groundwater
b. Vadose water
c. Meteoric water
d. Water in capillary fringe
1. Water from precipitation in the form of rain or snow
2. Water present in a zone of saturation
3. Water held in the unsaturated zone or zone of aeration
4. Water drawn somewhat above the water table by surface tension

Narayan Hari

Numerade Educator

01:22

Problem 15

What are two mechanisms by which anions may be held by soil mineral matter?

Lottie Adams

Numerade Educator

03:20

Problem 15

Large areas of central Kansas have vast deposits of halite. What is halite? What does this observation say about the geologic history of the area?

Ronald Prasad

Numerade Educator

01:33

Problem 16

What are the three major ways in which pesticides are degraded in or on soil?

Anitha Mary

Numerade Educator

02:12

Problem 16

What is the distinction between weathering and erosion? Suggest ways in which air pollution may contribute to both phenomena.

Devin Lea

Numerade Educator

11:58

Problem 17

One way in which coal and other fossil fuels may be used without contributing to higher levels of greenhouse gas carbon dioxide in the atmosphere is through carbon sequestration by pumping carbon dioxide into mineral strata. Explain with a chemical reaction how formations of limestone (calcium carbonate) might be used for this purpose. Suggest how this might cause problems on the surface.

Danielle Ashley

Numerade Educator

03:33

Problem 17

Lime from lead mine tailings containing $0.5 \%$ lead was applied at a rate of 10 metric tons per acre of soil and worked into a depth of $20 \mathrm{~cm}$. The soil density was $2.0 \mathrm{~g} / \mathrm{cm}$. To what extent did this add to the burden of lead in the soil? There are 640 acres per square mile and $1,609 \mathrm{~m}$ per mile.

Christopher Dzorkpata

Numerade Educator

03:37

Problem 18

Deposits of iron minerals are often found where groundwater flows to the surface. Use a chemical reaction to explain this observation.

Shahina -

Numerade Educator

02:09

Problem 18

Match the soil or soil-solution constituent in the left column with the soil condition described on the right:
a. High $\mathrm{Mn}^{2+}$ content in soil solution
b. Excess $\mathrm{H}^{+}$
c. High $\mathrm{H}^{+}$and $\mathrm{SO}_4^{2-}$ concentrations
d. High organic content
1. "Cat clays" containing initially high levels of pyrite, $\mathrm{FeS}_2$
2. Soil in which biodegradation has not occurred to a great extent
3. Waterlogged soil
4. Soil, the fertility of which can be improved by adding limestone

Christina Sorrentino

Numerade Educator

03:37

Problem 18

Deposits of iron minerals are often found where groundwater flows to the surface. Use a chemical reaction to explain this observation.

Shahina -

Numerade Educator

Problem 19

What are the processes occurring in soil that operate to reduce the harmful effects of pollutants?

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02:00

Problem 20

Under what conditions do the following reactions occur in soil? Name two detrimental effects that can result from these reactions.
$$
\begin{gathered}
\mathrm{MnO}_2+4 \mathrm{H}^{+}+2 e^{-} \rightarrow \mathrm{Mn}^{2+}+2 \mathrm{H}_2 \mathrm{O} \text { and } \\
\mathrm{Fe}_2 \mathrm{O}_3+6 \mathrm{H}^{+}+2 e^{-} \rightarrow 2 \mathrm{Fe}^{2+}+3 \mathrm{H}_2 \mathrm{O}
\end{gathered}
$$

Oluwapelumi Kolawole

Numerade Educator

00:48

Problem 21

What are four important effects of organic matter in soil?

Kayla Scholl

Numerade Educator

03:04

Problem 22

How might irrigation water treated with fertilizer containing potassium and ammonia become depleted of these nutrients in passing through humus-rich soil?

Maryam Riaz

Numerade Educator