WEEK 3: ACIDS & BASES

Acid

Donates H+ ions and forms hydronium ions (H3O+).

Base

Accepts H+ ions and can also be viewed as increasing the concentration of OH-.

Hydronium Ion

The ion formed when an acid donates a proton, H3O+.

pH

A logarithmic measure of the hydrogen ion concentration in a solution.

Ionised

A state of a molecule that has a charge due to the loss or gain of H+.

Protonated

Describes a molecule that has gained or held onto a proton.

Dissociated

A state where a molecule has lost a proton and may be charged or uncharged.

Conjugate Acid-Base Pair

A pair of species that differ by the presence or absence of a proton.

pKa

A value that indicates the acidity of a particular molecule; lower pKa indicates a stronger acid.

Henderson-Hasselbach Equation

An equation that relates pH, pKa, and the ratio of the concentrations of ionized and unionized forms of a drug.

Buffer

A solution that resists changes in pH, typically a mixture of an acid and its conjugate base.

Acidic Conditions

Conditions where pH is less than the pKa of a drug, leading to more H+ ions.

Alkaline Conditions

Conditions where pH is greater than the pKa of a drug, leading to fewer H+ ions.

Chemical Stability

The tendency of a solution to resist changes in composition, which can be affected by pH.

Functional Groups

Specific groups of atoms responsible for the characteristic reactions of a compound.

Ionization

The process by which a molecule gains or loses protons to become charged.