ch 10

Question 1

what is the process of hydration

Answer 1

incorporation of water molecules into or between molecules or mineral crystal lattice without a chemcial reaction

Question 2

what is the process of acid base

Answer 2

exchange of a proton

Question 3

what is the process of precipitation/dissolution

Answer 3

formation or dissolution of a solid, usually involves hydration

Question 4

what is the process of adsorption/desorption

Answer 4

chemical interaction between chemical and surface

Question 5

what is the process of complexation

Answer 5

formation of an ion complex

Question 6

what is the process of partitioning

Answer 6

movement of a molecule from one phase into another

Question 7

what is carbonic acid

Answer 7

H2CO3

Question 8

what is the product of carbonic acid dissociating

Answer 8

HCO3-

Question 9

what is the second step of carbonic acid dissocation produce

Answer 9

CO32-

Question 10

how do the two K values for carbonic acid dissocation change with temperature and salinity

Answer 10

strongly increase with temperature and weakely decrease with salinity

Question 11

how can we estimate the distribution of all the forms of carbonic acid at differnt pHs

Answer 11

using pH and the two Kas

Question 12

what are the trends of common weak acids and bases in fresh versus salt water

Answer 12

seawater is inriched in carbonate forms indicating that processes in the ocean remove the other acids

freshwater is rich in silicate and carbonic forms

Question 13

what are the trends of common weak acids and bases in fsurface versus deep water

Answer 13

surface is lower in acids because they are removed in the surfcae

higher in deep water due ot thermohaline circulation, more time for things to accumulate due to respiration

more time for shells to dissolve and break down and the water is more acidic

Question 14

what happens when a strong acid is dissolved

Answer 14

it deprotonates entirelywh

Question 15

what happnes when a weak acid dissolves

Answer 15

only some of the acid wiill dissolve leading to equilibrium arrows

Question 16

what do weak acids act as

Answer 16

buffers to stabilize the pH in the ocean

a quick drop in pH indicates that all the product converted tot he weak acid form so now all other H+ goes towards changing the ph

Question 17

Most polyprotic acids and bases are

Answer 17

weak

Question 18

what is an important diprotic acid/base system in the ocean

Answer 18

carbonate system

keeps the ocean between 7.9 and 8.4 pH

Question 19

under what conditions does the second step of the carbonate system happen

Answer 19

in higher ph

Question 20

what is a complex

Answer 20

a substance formed by the union of simpler substances held together by chemical forces

dependent on properties of particular atomic structures rather than physical ones like chemical attraction

Question 21

what are the metals in complexes

Answer 21

lewis acids- accept electron donating ligands which are lewis bases

Question 22

what is a bronsted lowry acid

Answer 22

gives off one or more H+

Question 23

most transition metal can bind _ ligands

Answer 23

up to 6

Question 24

what is the equilibrium coefficient for complexatino

Answer 24

formation constant

Question 25

how are ligands categorized

Answer 25

by the number of binding sites that can form

ex. tridentate can form four metal lgand bonds

Question 26

what is a chelating ligand

Answer 26

a lingand that binds to a metal through multiple atoms

Question 27

how does the formation constant differ betwen chelating and monodentate ligands

Answer 27

it is higher for chelating ligands becaues of the chelate effect

Question 28

what is the chelate effect

Answer 28

chelating ligands are thermodynamically more stable than monodentate ligands

Question 29

charge and complxe formation of DOM

Answer 29

organic molecules from DOM are typically negatively charged forming complexes with metals

Question 30

what are the functional groups that form complexse with metals from DOM

Answer 30

R-COO-
R-S-
R2-NH
R-NH2

these multiple functional groups allow these ligands to chelate leading to a higher Kf

Question 31

competing formation

Answer 31

since in a real system tehre are many ligand that can interact with a metal, theere will be competition amongst ligands to form complexes allowing the ligands with the best Kf and concentration to win

Question 32

free ion complexatino is improtantt for

Answer 32

trace metals like

Mn
Co
Ni
Ag
Cd

Question 33

what are the most common compelxing agents for trace metals

Answer 33

OH-
Cl-
SO42-
CO32-
DOM

Question 34

what complexation agent is imporatnt in anoxic enviroments for trace metals

Answer 34

SO3-

Question 35

organic complexation is important for

Answer 35

Cu
Zn
Fe
Pb
Hg

Question 36

speciation effects of what are important

Answer 36

of the metal beacuse the conc of ligand greatly exceeds the metal

Question 37

what are the biological impacts of trace metal complexation

Answer 37

compelxed copper is less available and less toxic

Hg more available more toxic

Fe more available- good thing for algae

Question 38

what is the importance of irom complexes

Answer 38

irion is a limiting nutreint in ocean waters

iron fertilization- bc iron is rquired for the use of other elements

depends on which form the iron is supplied in- different organisms benifit differently

complexation is an effcetive way to dissolve iron and make it available - otherwise particulate iron if not quickly dissolved is lost for surface waters

Question 39

siderophores

Answer 39

small ligands secreted by bact to bring iron across membranes

l

Question 40

how is light involved in iron complexation

Answer 40

it brings iron from between the reduced and oxidized form

Question 41

weather and its effcet on iron

Answer 41

cold weather increases erosion of sant and silicates and iron are released

high iron stimulates growth of algae leads to decreased Co2 because they remove it from air and this leads to colder temperatures