How Can Chemical Equilbirum Help You?

In studying aquatic chemistry, there are many applications for chemical equilibria.

For instance, it is possible to be looking into the mechanisms that control the

movement of solutes in groundwater or surface water; or one could be interested in

controlling the pH, alkalinity or corrosivity of drinking water; or one may be interested

in the toxicological effects of dissolved metals on the biota. Actually, there are so

many possible applications of chemical equilibria to aqueous systems that it would be

hard to list them all.

For a person interested in aquatic systems (or soil systems, or marine systems, for

that matter) a few assumptions hold true: Dissolved ions in solution interact with each

other (form complexes), interact with particulate surfaces (adsorb) and possibly form

solid phases (precipitate). In a typical natural

system, say a stream water, there may be 10 to

20 major chemical components dissolved in solution. These components have the

potential to form hundreds of dissolved chemical complexes, solids phases or

adsorbed species. Some of these chemical species may be biologically active or

even toxic while others may be inert. All of this depends on factors like the total

concentration of each component, the pH, pe, ionic strength and temperature.

This is where calculating chemical equilibrium is helpful. As the name implies,

chemical equilibrium assumes that all reactions have gone to completion and are

in equilibrium with one another. So time dependent reactions -- those reactions

that have kinetic restrictions -- are not addressed in this approach. In essence, the

chemical equilibrium approach provides you with a thermodynamic snapshot of your system: the pH, ionic strength, the

distribution of dissolved chemical species, how much solid phase formed, etc. This is the type of information that is

critical to understanding what happens chemically in water.

In studying aquatic chemistry, there are many applications for chemical equilibria. For instance, it is possible to be

looking into the mechanisms that control the movement of solutes in groundwater or surface water; or one could be

interested in controlling the pH, alkalinity or corrosivity of drinking water; or one may be interested in the toxicological

effects of dissolved metals on the biota. Actually, there are so many possible applications of chemical equilibria to

aqueous systems that it would be hard to list them all.

For a person interested in aquatic systems (or soil systems, or marine systems, for that matter) a few assumptions hold

true: Dissolved ions in solution interact with each other (form complexes), interact with particulate surfaces (adsorb)

and possibly form solid phases (precipitate). In a typical natural system, say a stream water, there may be 10 to 20

major chemical components dissolved in solution. These components have the potential to form hundreds of dissolved

chemical complexes, solids phases or adsorbed species. Some of these chemical species may be biologically active or

even toxic while others may be inert. All of this depends on factors like the total concentration of each component, the

pH, pe, ionic strength and temperature.

This is where calculating chemical equilibrium is helpful. As the name implies, chemical equilibrium assumes that all

reactions have gone to completion and are in equilibrium with one another. So time dependent reactions -- those

reactions that have kinetic restrictions -- are not addressed in this approach. In essence, the chemical equilibrium

approach provides you with a thermodynamic snapshot of your system: the pH, ionic strength, the distribution of

dissolved chemical species, how much solid phase formed, etc. This is the type of information that is critical to

understanding what happens chemically in water.

In studying aquatic chemistry, there are many applications for chemical equilibria. For instance, it is possible to be

looking into the mechanisms that control the movement of solutes in groundwater or surface water; or one could be

interested in controlling the pH, alkalinity or corrosivity of drinking water; or one may be interested in the toxicological

effects of dissolved metals on the biota. Actually, there are so many possible applications of chemical equilibria to

aqueous systems that it would be hard to list them all.

For a person interested in aquatic systems (or soil systems, or marine systems, for that matter) a few assumptions hold

true: Dissolved ions in solution interact with each other (form complexes), interact with particulate surfaces (adsorb)

and possibly form solid phases (precipitate). In a typical natural system, say a stream water, there may be 10 to 20

major chemical components dissolved in solution. These components have the potential to form hundreds of dissolved

chemical complexes, solids phases or adsorbed species. Some of these chemical species may be biologically active or

even toxic while others may be inert. All of this depends on factors like the total concentration of each component, the

pH, pe, ionic strength and temperature.

This is where calculating chemical equilibrium is helpful. As the name implies, chemical equilibrium assumes that all

reactions have gone to completion and are in equilibrium with one another. So time dependent reactions -- those

reactions that have kinetic restrictions -- are not addressed in this approach. In essence, the chemical equilibrium

approach provides you with a thermodynamic snapshot of your system: the pH, ionic strength, the distribution of

dissolved chemical species, how much solid phase formed, etc. This is the type of information that is critical to

understanding what happens chemically in water.

In studying aquatic chemistry, there are many applications for chemical equilibria. For instance, it is possible to be

looking into the mechanisms that control the movement of solutes in groundwater or surface water; or one could be

interested in controlling the pH, alkalinity or corrosivity of drinking water; or one may be interested in the toxicological

effects of dissolved metals on the biota. Actually, there are so many possible applications of chemical equilibria to

aqueous systems that it would be hard to list them all.

For a person interested in aquatic systems (or soil systems, or marine systems, for that matter) a few assumptions hold

true: Dissolved ions in solution interact with each other (form complexes), interact with particulate surfaces (adsorb)

and possibly form solid phases (precipitate). In a typical natural system, say a stream water, there may be 10 to 20

major chemical components dissolved in solution. These components have the potential to form hundreds of dissolved

chemical complexes, solids phases or adsorbed species. Some of these chemical species may be biologically active or

even toxic while others may be inert. All of this depends on factors like the total concentration of each component, the

pH, pe, ionic strength and temperature.

This is where calculating chemical equilibrium is helpful. As the name implies, chemical equilibrium assumes that all

reactions have gone to completion and are in equilibrium with one another. So time dependent reactions -- those

reactions that have kinetic restrictions -- are not addressed in this approach. In essence, the chemical equilibrium

approach provides you with a thermodynamic snapshot of your system: the pH, ionic strength, the distribution of

dissolved chemical species, how much solid phase formed, etc. This is the type of information that is critical to

understanding what happens chemically in water.

In studying aquatic chemistry, there are many applications for chemical equilibria. For

instance, it is possible to be looking into the mechanisms that control the movement of

solutes in groundwater or surface water; or one could be interested in controlling the

pH, alkalinity or corrosivity of drinking water; or one may be interested in the

toxicological effects of dissolved metals on the biota. Actually, there are so many

possible applications of chemical equilibria to aqueous systems that it would be hard to

list them all.

For a person interested in aquatic systems (or soil systems, or marine systems, for that

matter) a few assumptions hold true: Dissolved ions in solution interact with each other

(form complexes), interact with particulate surfaces (adsorb) and possibly form solid

phases (precipitate). In a typical natural system, say a stream water, there may be 10 to

20 major chemical components dissolved in solution. These components have the

potential to form hundreds of dissolved chemical complexes, solids phases or adsorbed

species. Some of these chemical species may be biologically active or even toxic while

others may be inert. All of this depends on factors like the total concentration of each

component, the pH, pe, ionic strength and temperature.

This is where calculating chemical equilibrium is helpful. As the name implies, chemical

equilibrium assumes that all reactions have gone to completion and are in equilibrium

with one another. So time dependent reactions -- those reactions that have kinetic

restrictions -- are not addressed in this approach. In essence, the chemical equilibrium

approach provides you with a thermodynamic snapshot of your system: the pH, ionic strength, the distribution of

dissolved chemical species, how much solid phase formed, etc. This is the type of information that is critical to

understanding what happens chemically in water.

In studying aquatic chemistry, there are many applications for chemical equilibria. For

instance, it is possible to be looking into the mechanisms that control the movement of

solutes in groundwater or surface water; or one could be interested in controlling the pH,

alkalinity or corrosivity of drinking water; or one may be interested in the toxicological

effects of dissolved metals on the biota. Actually, there are so many possible

applications of chemical equilibria to aqueous systems that it would be hard to list them

all.

For a person interested in aquatic systems (or soil systems, or marine systems, for that

matter) a few assumptions hold true: Dissolved ions in solution interact with each other

(form complexes), interact with particulate surfaces (adsorb) and possibly form solid

phases (precipitate). In a typical natural system, say a stream water, there may be 10 to

20 major chemical components dissolved in solution. These components have the potential to form hundreds of

dissolved chemical complexes, solids phases or adsorbed species. Some of these

chemical species may be biologically active or even toxic while others may be inert. All of

this depends on factors like the total concentration of each component, the pH, pe, ionic

strength and temperature.

This is where calculating chemical equilibrium is helpful. As the name implies, chemical

equilibrium assumes that all reactions have gone to completion and are in equilibrium

with one another. So time dependent reactions -- those reactions that have kinetic

restrictions -- are not addressed in this approach. In essence, the chemical equilibrium

approach provides you with a thermodynamic snapshot of your system: the pH, ionic strength, the distribution of

dissolved chemical species, how much solid phase formed, etc. This is the type of information that is critical to

understanding what happens chemically in water.

How Can Chemical Equilibrium
Help You?

In studying aquatic chemistry, there are many applications for chemical equilibria. For instance, it is possible to be looking into the mechanisms that control the movement of solutes in groundwater or surface water; or one could be interested in controlling the pH, alkalinity or corrosivity of drinking water; or one may be interested in the toxicological effects of dissolved metals on the biota. Actually, there are so many possible applications of chemical equilibria to aqueous systems that it would be hard to list them all.

For a person interested in aquatic systems (or soil systems, or marine systems, for that matter) a few assumptions hold true: Dissolved ions in solution interact with each other (form complexes), interact with particulate surfaces (adsorb) and possibly form solid phases (precipitate). In a typical natural system, say a stream water, there may be 10 to 20 major chemical components dissolved in solution. These components have the potential to form hundreds of dissolved chemical complexes, solids phases or adsorbed species. Some of these chemical species may be biologically active or even toxic while others may be inert. All of this depends on factors like the total concentration of each component, the pH, pe, ionic strength and temperature.

This is where calculating chemical equilibrium is helpful. As the name implies, chemical equilibrium assumes that all reactions have gone to completion and are in equilibrium with one another. So time dependent reactions -- those reactions that have kinetic restrictions -- are not addressed in this approach. In essence, the chemical equilibrium approach provides you with a thermodynamic snapshot of your system: the pH, ionic strength, the distribution of dissolved chemical species, how much solid phase formed, etc. This is the type of information that is critical to understanding what happens chemically in water.