Water Chemistry

Acids & Bases

Metal Speciation

Predominance

Redox

Surfaces

100

Which of these parameters is not conserved:

a)Alkalinity

b)Total metal (Me_Tot)

c)pH

d)Total inorganic carbon (C_T)

c) pH

100

Which metal forms the strongest complexes with organic ligands?

a)Fe

b)Cd

c)Cu

d)Se

c)Cu

100

The predominant hydrolysis species depends on __.

a)pH and PCO2

b)Ks0

c)pH

d)[ligands]

c)pH

100

Which redox couple occurs at the lowest pe?

a)SO₄^2-

b)NO₃^-/N₂

c)CO₂/CH₄

d)H₂O/H₂

100

Surface chemistry is likely to be most important to contaminant fate in:

a)Groundwater

b)Lakes

c)Oceans

d)Rivers

a)Groundwater

200

The typical pH of rainwater is:

a)~7

b)8-9

c)<5

d)5-6

200

Formation of CuCO₃⁰ can be explained by ___.

a)electrostatics

b)inner-sphere complexation

c)hydration sphere mediation

d)hydrolysis

b)inner-sphere complexation

200

More reduced species are __ on a Pourbaix diagram.

a)At the bottom

b)At the top

c)On the left

d)On the right

a)At the bottom

200

You are standing in a marsh at the edge of SF Bay. You can smell hydrogen sulfide. Is there likely to be nitrate in the marsh water?

a)Yes, [NO₃^-] > 1 mM

b)No

c)Cannot tell from the information given

d)Yes, [NO₃^-] < 1 mM

b)No

200

Which nutrient's speciation is most affected by adsorption?

a)Nitrate

b)Ammonium

c)Iron

d)Phosphate

d) Phosphate

300

Si(OH)₄ is a ___ acid.

a)Monoprotic

b)Strong

c)Diprotic

d)Polyprotic

c)Diprotic

300

CdOH⁺ + H₂O --> Cd(OH)₂ + H⁺

a)K_H2

b)*K_H2

c) beta_Cd(OH)2

d)*beta_Cd(OH)2

b)*K_H2

300

In the solid region of a predominance diagram, [Me]_diss ___.

a)=[Me]_TOT

b)>[Me]_TOT

c)Cannot be determined

d)Is set by K_s0

300

In what oxidation state does uranium form a solid?

a)U(1)

b)U(2)

c)U(4)

d)U(6)

c)U(4)

300

What property of a solid is most important in determining its contribution to contaminant adsorption?

a)Metal type (Al vs. Si vs. Fe)

b)Particle size

c)Surface area

d)Mass

c)Surface area

400

A water sample contains 100 mg/L Alk as CaCO₃, what is the alkalinity?

a)100 mM

b)1 mM

c)2 mM

d)200 mM

c)2 mM

400

Which binds with Mg(II) most strongly?

a)Organic sulfides

b)Carboxylic acid groups

c)Chloride

d)Sulfate

400

Ferrihydrite (Fe(OH)_3(s), K_s0=10^-37.11) and geothite (FeOOH_(s), K_s0=10^-41.50) are both oversaturated. Which will form?

a)Ferrihydrite

b)Geothite

c)Whichever has a higher saturation index

d)Whichever has a lower saturation index

a)Ferrihydrite

400

What effect does high alkalinity have in distribution systems?

a)Causes corrosion of iron pipes

b)Causes corrosion of lead pipes

c)Removes lead via precipitation

d)Results in formation of gibbsite scale

c)Removes lead via precipitation

400

What is the regulatory cutoff for dissolved species?

a)0.22 um

b)0.45 um

c)0.7 um

d)1 um

b)0.45 um

500

Acid rain will have the most effect on the pH of a lake with ___.

a)The water column shaded by plants

b)Limestone sediments

c)Effluent from a wastewater treatment plant

d)Added nitrate present

500

Which ligand is responsible for most of the complexation of mercury in estuaries?

a)Sulfide

b)Sulfate

c)Chloride

d)Carbonate

a)Sulfide

500

During corrosion of an iron pipe, in which direction does the speciation move on a pe-pH diagram?

a)Mostly up

b)Mostly down

c)Mostly left

d)Mostly right

a)Mostly up

500

What effect could adding methanol have during biological wastewater treatment?

a)Increase nitrate removal

b)Increase dissolved oxygen concentration

c)Cause Fe(III) to precipitate

d)Decrease complexation of metals by sulfide

a)Increase nitrate removal

500

Which type of clay has the greatest sorption capacity?

a)Kaolinite

b)1:1 clays

c)Silica

d)Montmorillonite