Module 6 definitions

Acid

proton donor

Amphoteric substance

the fundamental unit of which elements are composed

Arrhenius solution

a concept postulating that acids produce hydrogen ions in aqueous solutions whereas bases produce hydroxide ions

Aqueous solution

solutions in which water is the dissolving medium or solvent

Base

proton acceptor

Bronsted-Lory model

a model proposing that an acid is a proton donor and that a base is a proton acceptor

Buffered solution

a solution where there is a presence of a weak acid and its conjugate base; a solution that resists a change in its pH when either hydroxide ions or protons are added

Concentrated

refers to a solution in which a relatively large amount of solute is dissolved in a solution

Conjugate acid

the species formed when a proton is added to a base

Conjugate acid-base pair

2 species related to each other by the donating and accepting of a single proton

Conjugate base

what remains of an acid molecule after a proton is lost

Dilute

refers to a solution where a relatively small amount of solute is dissolved

Dilution

the process of adding solvent to lower the concentration of solute in a solution

Hydronium ion

the H₃O⁺ ion; a hydrated proton

Ion-product constant

(Kw) the equilibrium constant for the autoionization of water; K_w = [H⁺][OH^-]. At 25C, Kw = 1.0 °C 10^-14

Mass percent/weight percent

the percent by mass of a component of a mixture or of a given element in a compound

Molarity (M)

moles of solute per volume of solution in litres

Neutralisation reactions

an acid-base reaction

Organic acid

acids with a carbon-atom backbone and a carbonyl group

Oxyacid

acids in which the acidic proton is attached to an oxygen atom

pH scale

a log scale based on 10 and equal to -log[H⁺]

Saturated

refers to a solution that contains as much solute as can be dissolved in that solution

Solution

a homogenous mixture

Solvent

the dissolving medium in a solution

Standard solution

a solution in which the concentration is accurately known

Strong acid

an acid that completely dissociates (ionizes) to produce H⁺ ion and the conjugate base

Unsaturated solution

refers to solution in which more solute can be dissolved than is dissolved already

Weak acid

an acid that dissociates only to a slight extent in aqueous solution