aqueous

(adjective)

Consisting mostly of water.

Related Terms

Examples of aqueous in the following topics:

  • Electrolysis of Sodium Chloride

    • Two commonly used methods of electrolysis involve molten sodium chloride and aqueous sodium chloride, which give different products.
    • Two commonly used methods of electrolysis involve molten sodium chloride and aqueous sodium chloride.
    • What happens when we have an aqueous solution of sodium chloride?
    • Electrolysis of aqueous NaCl results in hydrogen and chloride gas.
    • Predict the products of electrolysis of sodium chloride under molten and aqueous conditions

  • The Arrhenius Definition

    • It was used to provide a modern definition of acids and bases, and followed from Arrhenius's work with Friedrich Wilhelm Ostwald in establishing the presence of ions in aqueous solution in 1884.
    • In other words, an acid increases the concentration of H+ ions in an aqueous solution.
    • In other words, a base increases the concentration of OH- ions in an aqueous solution.
    • The Arrhenius definitions of acidity and alkalinity are restricted to aqueous solutions and refer to the concentration of the solvated ions.
    • Thus, the Arrhenius definition can only describe acids and bases in an aqueous environment.

  • Weak Bases

    • In aqueous solution, a weak base reacts incompletely with water to yield hydroxide ions.
    • A weak base is a chemical base that does not ionize fully in an aqueous solution.
    • The pH of bases in aqueous solution ranges from greater than 7 (the pH of pure water) to 14 (though some bases have pH values greater than 14).

  • Precipitation Reactions

    • Precipitation reactions transform ions into an insoluble salt in aqueous solution.
    • Precipitation refers to a chemical reaction that occurs in aqueous solution when two ions bond together to form an insoluble salt, which is known as the precipitate.
    • Aqueous silver nitrate (AgNO3) is added to a solution containing potassium chloride (KCl), and the precipitation of a white solid, silver chloride (AgCl), is observed:

  • Acid Dissociation Constant (Ka)

    • Ka is the equilibrium constant for the following dissociation reaction of an acid in aqueous solution:
    • As with all equilibrium constants, the value of Ka is determined by the concentrations (in mol/L) of each aqueous species at equilibrium.
    • A strong acid is almost completely dissociated in aqueous solution; it is dissociated to the extent that the concentration of the undissociated acid becomes undetectable. pKa values for strong acids can be estimated by theoretical means or by extrapolating from measurements in non-aqueous solvents with a smaller dissociation constant, such as acetonitrile and dimethylsulfoxide.

  • Strong Acids

    • A strong acid ionizes completely in an aqueous solution by losing one proton, according to the following equation:
    • More precisely, the acid must be stronger in aqueous solution than a hydronium ion (H+), so strong acids have a pKa < -1.74.
    • This generally means that in aqueous solution at standard temperature and pressure, the concentration of hydronium ions is equal to the concentration of strong acid introduced to the solution.
    • Due to the complete dissociation of strong acids in aqueous solution, the concentration of hydronium ions in the water is equal to the total concentration (ionized and un-ionized) of the acid introduced to solution:
    • A strong acid ionizes completely in an aqueous solution by losing one proton (H+).

  • Solubility Product

    • The solubility product is the equilibrium constant representing the maximum amount of solid that can be dissolved in aqueous solution.
    • The solubility product constant (Ksp) is the equilibrium constant for a solid that dissolves in an aqueous solution.

  • Copper

    • In aqueous solutions, copper(II) exists as [Cu(H2O)6]2+.
    • Adding aqueous sodium hydroxide causes the precipitation of light blue solid copper (II) hydroxide.
    • Aqueous ammonia results in the same precipitate.
    • In aqueous solutions, copper(II) exists as [Cu(H2O)6]2+.
    • Aqueous ammonia results in the same precipitate.

  • Molecular, Ionic, and Complete Ionic Equations

    • In the molecular equation, electrolytes are written as salts followed by (aq) to indicate that the electrolytes are completely dissociated into their constituent ions; the (aq) designation indicates that the ions are in aqueous solution.
    • For example, aqueous calcium chloride's reaction with aqueous silver nitrate can be written as follows:

  • Writing Chemical Equations

    • For example, a compound in the gas state would be indicated by (g), solid (s), liquid (l), and aqueous (aq).
    • Aqueous means dissolved in water; it is a common state of matter for acids, bases, and dissolved ionic compounds.
    • When a baking soda volcano is made by mixing vinegar (dilute aqueous acetic acid) and baking soda (sodium bicarbonate), the resulting evolution of gas occurs via the following reaction: