"Aqueous" redirects here. For the fluid in the eye, see Aqueous humour.
An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would be represented as Na+(aq) + Cl−(aq). The word aqueous (which comes from aqua) means pertaining to, related to, similar to, or dissolved in, water.[1] As water is an excellent solvent and is also naturally abundant, it is a ubiquitous solvent in chemistry. Since water is frequently used as the solvent in experiments, the word solution refers to an aqueous solution, unless the solvent is specified.[2]
The first solvation shell of a sodium ion dissolved in water
Substances that are hydrophobic ('water-fearing') do not dissolve well in water, whereas those that are hydrophilic ('water-friendly') do. An example of a hydrophilic substance is sodium chloride. In an aqueous solution the hydrogen ions (H+) and hydroxide ions (OH−) are in Arrhenius balance ([H+][OH−] = Kw = 1 x 10−14 at 298 K). Acids and bases are aqueous solutions, as part of their Arrhenius definitions.[1] An example of an Arrhenius acid is hydrogen chloride (HCl) because of its dissociation of the hydrogen ion when dissolved in water. Sodium hydroxide (NaOH) is an Arrhenius base because it dissociates the hydroxide ion when it is dissolved in water.[2]
Aqueous solutions may contain, especially in the alkaline zone or subjected to radiolysis, hydrated atomic hydrogen and hydrated electrons.
Electrolytes
Aqueous solutions that conduct electric current efficiently contain strong electrolytes, while ones that conduct poorly are considered to have weak electrolytes. Those strong electrolytes are substances that are completely ionized in water, whereas the weak electrolytes exhibit only a small degree of ionization in water.[1] The ability for ions to move freely through the solvent is a characteristic of an aqueous strong electrolyte solution. The solutes in a weak electrolyte solution are present as ions, but only in a small amount.[2]
Nonelectrolytes are substances that dissolve in water yet maintain their molecular integrity (do not dissociate into ions). Examples include sugar, urea, glycerol, and methylsulfonylmethane (MSM).
Reactions
Reactions in aqueous solutions are usually metathesis reactions. Metathesis reactions are another term for double-displacement; that is, when a cation displaces to form an ionic bond with the other anion. The cation bonded with the latter anion will dissociate and bond with the other anion.[1]
A common metathesis reaction in aqueous solutions is a precipitation reaction. This reaction occurs when two aqueous strong electrolyte solutions mix and produce an insoluble solid, also known as a precipitate. The ability of a substance to dissolve in water is determined by whether the substance can match or exceed the strong attractive forces that water molecules generate between themselves. If the substance lacks the ability to dissolve in water, the molecules form a precipitate.[2]
When writing the equations of precipitation reactions, it is essential to determine the precipitate. To determine the precipitate, one must consult a chart of solubility. Soluble compounds are aqueous, while insoluble compounds are the precipitate. There may not always be a precipitate. Complete ionic equations and net ionic equations are used to show dissociated ions in metathesis reactions. When performing calculations regarding the reacting of one or more aqueous solutions, in general one must know the concentration, or molarity, of the aqueous solutions.
See also
Look up aqueous solution in Wiktionary, the free dictionary.
^ abcdZumdahl, Steven (1997). Chemistry (4th ed.). Boston, MA: Houghton Mifflin Company. pp. 133–145. ISBN9780669417944.
^ abcdAtkins, Peter (19 March 2004). Chemical Principles: The Quest for Insight (3rd ed.). New York, NY: W.H. Freeman and Company. pp. F61–F64. ISBN0-7167-5701-X.
^"Solutions". Washington University Chemistry Department. Washington University. Retrieved 13 April 2018.
January 16, 2023
aqueous, solution, aqueous, redirects, here, fluid, aqueous, humour, aqueous, solution, solution, which, solvent, water, mostly, shown, chemical, equations, appending, relevant, chemical, formula, example, solution, table, salt, sodium, chloride, nacl, water, . Aqueous redirects here For the fluid in the eye see Aqueous humour An aqueous solution is a solution in which the solvent is water It is mostly shown in chemical equations by appending aq to the relevant chemical formula For example a solution of table salt or sodium chloride NaCl in water would be represented as Na aq Cl aq The word aqueous which comes from aqua means pertaining to related to similar to or dissolved in water 1 As water is an excellent solvent and is also naturally abundant it is a ubiquitous solvent in chemistry Since water is frequently used as the solvent in experiments the word solution refers to an aqueous solution unless the solvent is specified 2 The first solvation shell of a sodium ion dissolved in water A non aqueous solution is a solution in which the solvent is a liquid but is not water 3 See also Solvent and Inorganic nonaqueous solvent Contents 1 Characteristics 2 Electrolytes 3 Reactions 4 See also 5 ReferencesCharacteristics EditSubstances that are hydrophobic water fearing do not dissolve well in water whereas those that are hydrophilic water friendly do An example of a hydrophilic substance is sodium chloride In an aqueous solution the hydrogen ions H and hydroxide ions OH are in Arrhenius balance H OH Kw 1 x 10 14 at 298 K Acids and bases are aqueous solutions as part of their Arrhenius definitions 1 An example of an Arrhenius acid is hydrogen chloride HCl because of its dissociation of the hydrogen ion when dissolved in water Sodium hydroxide NaOH is an Arrhenius base because it dissociates the hydroxide ion when it is dissolved in water 2 Aqueous solutions may contain especially in the alkaline zone or subjected to radiolysis hydrated atomic hydrogen and hydrated electrons Electrolytes EditAqueous solutions that conduct electric current efficiently contain strong electrolytes while ones that conduct poorly are considered to have weak electrolytes Those strong electrolytes are substances that are completely ionized in water whereas the weak electrolytes exhibit only a small degree of ionization in water 1 The ability for ions to move freely through the solvent is a characteristic of an aqueous strong electrolyte solution The solutes in a weak electrolyte solution are present as ions but only in a small amount 2 Nonelectrolytes are substances that dissolve in water yet maintain their molecular integrity do not dissociate into ions Examples include sugar urea glycerol and methylsulfonylmethane MSM Reactions EditReactions in aqueous solutions are usually metathesis reactions Metathesis reactions are another term for double displacement that is when a cation displaces to form an ionic bond with the other anion The cation bonded with the latter anion will dissociate and bond with the other anion 1 A common metathesis reaction in aqueous solutions is a precipitation reaction This reaction occurs when two aqueous strong electrolyte solutions mix and produce an insoluble solid also known as a precipitate The ability of a substance to dissolve in water is determined by whether the substance can match or exceed the strong attractive forces that water molecules generate between themselves If the substance lacks the ability to dissolve in water the molecules form a precipitate 2 When writing the equations of precipitation reactions it is essential to determine the precipitate To determine the precipitate one must consult a chart of solubility Soluble compounds are aqueous while insoluble compounds are the precipitate There may not always be a precipitate Complete ionic equations and net ionic equations are used to show dissociated ions in metathesis reactions When performing calculations regarding the reacting of one or more aqueous solutions in general one must know the concentration or molarity of the aqueous solutions See also Edit Look up aqueous solution in Wiktionary the free dictionary Acid base reaction Acidity function Dissociation chemistry List of ions in pure water aqueous chemistry Metal ions in aqueous solution Properties of water Solubility Solvated electronReferences EditThis article needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed Find sources Aqueous solution news newspapers books scholar JSTOR April 2011 Learn how and when to remove this template message a b c d Zumdahl Steven 1997 Chemistry 4th ed Boston MA Houghton Mifflin Company pp 133 145 ISBN 9780669417944 a b c d Atkins Peter 19 March 2004 Chemical Principles The Quest for Insight 3rd ed New York NY W H Freeman and Company pp F61 F64 ISBN 0 7167 5701 X Solutions Washington University Chemistry Department Washington University Retrieved 13 April 2018 Retrieved from https en wikipedia org w index php title Aqueous solution amp oldid 1132541707, wikipedia, wiki, book, books, library,
