- "In chemistry, pH (pee-AYCH), also referred to as acidity, historically denotes 'potential of hydrogen' (or 'power of hydrogen')."
This topic covers the properties of acids and bases, including pH, pOH, buffers, and titrations.
Properties of Acids: This topic covers the physical and chemical properties of acids.
Properties of Bases: This topic covers the physical and chemical properties of bases.
pH Scale: This topic covers the pH scale and how it is used to measure the acidity or basicity of a substance.
Acid-Base Reactions: This topic covers the chemical reactions that occur between acids and bases.
Bronsted-Lowry Theory: This topic covers the Bronsted-Lowry theory of acids and bases, which defines an acid as a proton donor and a base as a proton acceptor.
Lewis Theory: This topic covers the Lewis theory of acids and bases, which defines an acid as an electron acceptor and a base as an electron donor.
Neutralization Reactions: This topic covers the chemical reactions that occur when an acid and a base are combined to form a salt and water.
Hydrolysis: This topic covers the chemical reaction in which a salt reacts with water to produce an acid and a base.
Strong acids: These are acids that readily donate protons (hydrogen ions) in aqueous solutions, and dissociate completely. Examples include hydrochloric acid (HCl), sulfuric acid (H2SO4), and nitric acid (HNO3).
Weak acids: These are acids that do not dissociate completely in aqueous solutions, and have a lower tendency to donate protons. Examples include acetic acid (CH3COOH), carbonic acid (H2CO3), and formic acid (HCOOH).
Organic acids: These are acids that contain a carbon atom. Examples include citric acid, lactic acid, and malic acid.
Inorganic acids: These are acids that do not contain a carbon atom. Examples include hydrochloric acid (HCl), sulfuric acid (H2SO4), and phosphoric acid (H3PO4).
Lewis acids: These are acids that can accept an electron pair from a donor molecule. Examples include boron trifluoride (BF3), aluminium chloride (AlCl3), and iron(III) oxide (Fe2O3).
Strong bases: These are bases that readily accept protons (hydrogen ions) in aqueous solutions, and dissociate completely. Examples include sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium hydroxide (Ca(OH)2).
Weak bases: These are bases that do not dissociate completely in aqueous solutions, and have a lower tendency to accept protons. Examples include ammonia (NH3), pyridine (C5H5N), and methylamine (CH3NH2).
Organic bases: These are bases that contain a nitrogen atom. Examples include pyridine, caffeine, and histidine.
Inorganic bases: These are bases that do not contain a nitrogen atom. Examples include hydroxide ion (OH-), oxide ion (O2-), and carbonate ion (CO32-).
Lewis bases: These are bases that can donate an electron pair to an acceptor molecule. Examples include ammonia (NH3), water (H2O), and pyridine (C5H5N).
- "It is a scale used to specify the acidity or basicity of an aqueous solution."
- "Acidic solutions are measured to have lower pH values than basic or alkaline solutions."
- "The pH scale is logarithmic and inversely indicates the activity of hydrogen ions in the solution."
- "pH = -log(aH+) ≈ -log([H+])"
- "At 25 °C (77°F), solutions with a pH less than 7 are acidic."
- "Solutions with a pH greater than 7 are basic."
- "Solutions with a pH of 7 at 25 °C are neutral (i.e. have the same concentration of H+ ions as OH− ions, i.e. the same as pure water)."
- "The neutral value of the pH depends on the temperature and is lower than 7 if the temperature increases above 25 °C."
- "The pH range is commonly given as zero to 14, but a pH value can be less than 0 for very concentrated strong acids or greater than 14 for very concentrated strong bases."
- "Primary pH standard values are determined using a concentration cell with transference by measuring the potential difference between a hydrogen electrode and a standard electrode such as the silver chloride electrode."
- "The pH of aqueous solutions can be measured with a glass electrode and a pH meter or a color-changing indicator."
- "Measurements of pH are important in chemistry, agronomy, medicine, water treatment, and many other applications."
- "It is a scale used to specify the acidity or basicity of an aqueous solution."
- "The pH scale is logarithmic and inversely indicates the activity of hydrogen ions in the solution."
- "Measurements of pH are important in... water treatment..."
- "The pH of aqueous solutions can be measured with a glass electrode and a pH meter or a color-changing indicator."
- "Acidic solutions (solutions with higher concentrations of hydrogen (H+) ions)..."
- "Measurements of pH are important in... agronomy..."
- "[H+] is the equilibrium molar concentration (mol/L) of H+ in the solution."