Acids and bases Flashcards
Arrhenius theory to explain an acid and base
Acids produce hydrogen ions (H+
/H3O+/hydronium ions) in aqueous
solution. Bases produce hydroxide ions (OH-) in aqueous solution.
Lowry-Brønsted theory to explain an acid and base
An acid is a proton (H+ion) donor. A base is a proton (H+ion) acceptor.
Strong acids
ionise completely in water to form a high concentration of H3O+ ions.
Examples of strong acids are hydrochloric acid, sulphuric acid and nitric acid.
Weak acids
ionise incompletely in water to form a low concentration of H3O+ions. Examples of weak acids are ethanoic acid and oxalic acid.
Strong bases
dissociate completely in water to form a high concentration of OHions.
Examples of strong bases are sodium hydroxide and potassium hydroxide.
Weak bases
dissociate/ionise incompletely in water to form a low concentration of OHions.
Examples of weak bases are ammonia, calcium carbonate, potassium carbonate,
calcium carbonate and sodium hydrogen carbonate.
Concentrated acids/bases
Contain a large amount (number of moles) of acid/base in proportion to the volume of water
Dilute acids/bases
Contain a small amount (number of moles) of acid/base in proportion to the volume of water.
hydrolysis
The reaction of a salt with water
equivalence point of a titration
As the point at which the acid/base has
completely reacted with the base/acid
endpoint of a titration
The point where the indicator changes colour.
Explain the auto-ionisation of water
The reaction of water with itself to form H3O
+ions and OHions.
Explain the pH scale
as a scale of numbers from 0 to 14 used to express the acidity or alkalinity of a solution
Define Kw
as the equilibrium constant for the ionisation of water or the ion product of water or the ionisation constant of water,
