Acid-base Theory, pH, pKa & pKb- go over it as coculations are needed

Aspirin, Ibuprofen, Diclofenac, Benzylpenicillin

Morphine, procaine, Benzocaine, Chloramphenicol

Ephedrine hydrochloride, sodium ibuprofen, potassium diclofenac

is a proton DONOR strong acid full ionisation weak acids partial ionisation

is a proton ACCEPTOR

act as an acid or base is called an AMPHOLYTE and is said to be AMPHOTERIC in nature.

known as Lowry-Brønsted conjugate acid-base pairs

The dissociation of a WEAK ACID in aqueous conditions can be represented as follows: HA + H2O A- + H3O+ The equilibrium constant (for a weak acid) may be expressed as follows: [H3O+][A-] Ka = ---------------- [HA] pKa = - log Ka The lower the pKa-the stronger the acid

The dissociation of a WEAK BASE in aqueous conditions can be represented as follows: B + H2O OH- + BH+ The equilibrium constant (for a weak base) may be expressed as follows: [OH-] [BH+] Kb = ------------- [B] pKb = - log Kb The lower the pKb-the stronger the base

pKa + pKb = pKw Where pKw is the negative log of the dissociation constant for water (Kw). At 25oC : pKw = 14.00

are electrolytes which can function as either acids or bases ( amino acids and proteins). Example: Over the pH range 3-9, glycine exists in solution predominantly in the form +NH3CH2COO-. Such a structure, having both positive and negative charges on the same molecule, is referred to as “ZWITTERION”: acidic conditions becomes main base basic conditions main molecule becomes acidic

polyprotic

pKa = pH at which 50 % of species are ionised. At  2 pH units away from pKa weak electrolytes are completely dissociated/undissociated The acidic drug is completely unionised at PHs up to 2 units below its PKA and virtually completely ionised at PH greater than 2 units above its Pka

is a weak

is a Weak Acid

is a compound that is ionised in solution. Electrolytes yield ions when dissolved in water and therefore could conduct an electric current through solution.

are substances that do not yield ions when dissolved in water and therefore do not conduct an electric current through the solution. Examples of non-electrolytes are: - Sucrose - Glycerin - Naphtalene - Urea - Steroids

will make a salt and the addition of water will make salt and oh-

Resistant to changes in pH. Usually a mixture of a weak acid and its salt (conjugate base), or of a weak base and its salt (conjugate acid).

is a decrease in the solubility of an ionic compound as a result of the addition of a common ion addition of an equal concentration of a salt with a common ion

Also known as “buffer efficiency”, “buffer index” and “buffer value is defined as the ratio of the increment of strong base (or acid) to the small change in pH brought about by this addition.