What is Aqueous solutions: Definition and 15 Discussions

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. As water is an excellent solvent and is also naturally abundant, it is a ubiquitous solvent in chemistry. Aqueous solution is water with a pH of 7.0 where the hydrogen ions (H+) and hydroxide ions (OH−) are in Arrhenius balance (10−7).
A non-aqueous solution is a solution in which the solvent is a liquid, but is not water. (See also Solvent and Inorganic nonaqueous solvent.)
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. Acids and bases are aqueous solutions, as part of their Arrhenius definitions.
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.
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.
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.
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).
When writing the equations of aqueous 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.
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. Solution concentration is given in terms of the form of the solute prior to it dissolving.
Aqueous solutions may contain, especially in the alkaline zone or subjected to radiolysis, hydrated atomic hydrogen and hydrated electrons.

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  1. neilparker62

    Order of Reactions occurring in aqueous solutions

    A well known rate of reaction experiment is the reaction between sodium thiosulphate and Hydrochloric acid in which colloidal Sulphur is produced. Over time this obscures a cross placed beneath the reaction vessel. Reaction time can then be measured for various concentrations of thiosulphate...
  2. J

    Which of the following aqueous solutions would test closet to pH 7

    Homework Statement >Which of the following aqueous solutions would test closet to 7 on the pH scale? $a) NaCl$, $b) Na_2CO_3$, $c) NaH_2PO_4$, $d) NaCN$ Homework EquationsThe Attempt at a Solution I don't understand this. So I tried writing chemical equations like for a), NaCl + H20 --> NaOH +...
  3. C

    Solubility of Calcium Oxalate in an Alcohol Solution?

    In searching through the literature for the solubility of calcium oxalate, I came across this post https://www.researchgate.net/post/Are_there_any_organic_inorganic_solvents_for_dissolving_Ca-oxalate I am not sure where the people answering this question have gotten the information that calcium...
  4. neilparker62

    B Equation for Conductivity of Aqueous Solutions

    I have found a lot of data and graphs showing conductivity (micro-mhos) vs % by weight of various salt solutions. The salts for which graphs appear particularly linear are those of alkali Earth metals - eg sodium, potassium - KI, KBr, KCl etc. Is there a theoretical equation for conductivity vs...
  5. T

    Electrolysis of dilute aqueous solutions

    Homework Statement If dilute, aqueous magnesium bromide is electrolyzed, one product is formed at each electrode. Identify the product, state the electrode it occurs at (anode or cathode) and state a reason for your choice of product. Homework Equations Mg2+(aq) + 2e- --> Mg(s) E°red = -2.37 V...
  6. T

    Determine the equilibrium pH of aqueous solutions for the following strong acids

    Determine the equilibrium pH of aqueous solutions for the following strong acids or bases: (a) 257mg/L of HSO4- ; (b) 10nM NaOH ; (c) 75ug/L of HNO3
  7. M

    Oxoacid strengths in aqueous solutions

    Hey there, My textbook doesn't expand on this much and I'm unsure if I'm just not seeing some obvious connection; I'd appreciate it if someone could clarify this for me. I'm studying the Bronsted-Lowry theory and the strength of binary and ternary acids. I understand how, for example, H2SO4...
  8. U

    Acid-Base Chemistry in Aqueous Solutions

    Homework Statement What are the final hydrogen ion concentration and pH of of a solution obtained by mixing 400 mL of 0.2 M NaOH with 150 mL of 0.1 M H3PO4? pKa's are 2.12, 7.21, 12.32 Homework Equations Henderson-Hasselbach: pH = pKa + log [b]/[a] The Attempt at a Solution 0.2 M...
  9. F

    Troubleshooting Evaporation with a Rotary Evaporator

    Hy ! I have a problem and I need ur help.I tried to evaporate the water from a solution using the rotary evaporator but it didnt work.I don't know what i did wrong.Maybe u can help me or tell me which other method can I use? Thank u Greetings
  10. ~christina~

    Aqueous solutions and whether they are acidic/basic/neutral

    This isn't a homework question but a general question which I should know the answer to but am not sure. If you have a basic/acidic compound and add it to water to form an aqueous solution, the water should turn basic/acidic respectively, right? no exception? Thank you
  11. B

    Classifying Aqueous Solutions: Acids, Bases, or Neutral?

    Homework Statement Classify each of these aqueous solutions as acidic, neutral, or basic. A. HI(aq) B. NaCl(aq) C. RbOH(aq) Homework Equations The Attempt at a Solution A. HI(aq) is acidic B. NaCl(aq) is neutral C. RbOH(aq) is basic Am I right, wrong?!
  12. J

    Preparing Aqueous Solutions for Chemistry Students

    Chem problem need help... Homework Statement How would you prepare the following aqueous solutions? (a) 1.10 kg of 0.0515 m ethanol (C2H5OH) from ethanol and water Add___ g C2H5OH to ____ g H2O. (b) 511 g of 15.0 mass % HCl from 35.3 mass % HCl Add___ g of 35.3% HCl to ___ g of water...
  13. P

    Measuring pH of Aqueous Solutions Containing NaOH

    In the textbook it stated "In aqeous solutions, the concentration of hydronium ions is always related to the concentration of hyroxide ions. Therefore we can still measure or calculate the pH of solutions of bases like NaOH, even though they are not acidic." The book also stated that pH is a...
  14. Astronuc

    Conference on Water, Steam, and Aqueous Solutions for Electric Power

    – Advances in Science and Technology – Proceeings of the 14th International Conference on the Properties of Water and Steam Editors: Masaru Nakahara, Nobuyuki Matubayasi, Masakatsu Ueno, Kenji Yasuoka and Koichi Watanabe http://www.iapws.jp/proceedings.html Some very useful and...
  15. P

    Finding major species in aqueous solutions

    Which of the following are correct statements ? a) In an aqueous solution of NH4Cl, H2O, NH4+ and Cl-are the major species present b) In an aqueous solution of NaCH3CO2, H2O, Na+ and HCH3CO2 are the major species present c) In an aqueous solution of HCN, H2O, H3O+...