Module 5 Pharmaceutical Aids & Necessities PDF

University of San Agustin - Iloilo City College of Health and Allied Medical Professions - Pharmacy Department  HCl(g) H+(aq) + Cl-(aq) arrhenius acid NaOH(s) Na+(aq) + OH-(aq) arrhenius base Limitations because acids and bases were defined in terms of ions obtaine...

University of San Agustin - Iloilo City College of Health and Allied Medical Professions - Pharmacy Department  HCl(g) H+(aq) + Cl-(aq) arrhenius acid NaOH(s) Na+(aq) + OH-(aq) arrhenius base Limitations because acids and bases were defined in terms of ions obtained from water, the Arrhenius concept applied only to substances in aqueous solution the Arrhenius definition predicted that only substances that dissolve in water to produce H+ and OH− ions should exhibit the properties of acids and bases, respectively. NH3(s) + HCl(g) NH4Cl(s) base acid acid base conjugate conjugate acid base The Bronsted–Lowry definition of an acid is essentially the same as the Arrhenius definition, except that it is not restricted to aqueous solutions. The Brønsted–Lowry definition of a base, however, is far more general because the hydroxide ion is just one of many substances that can accept a proton. NH3(s) + HCl(g) NH4Cl(s) base acid Ammonia, for example, reacts with a proton to form NH4+. In the reaction, NH3 is a Bronsted–Lowry base and HCl is a Bronsted–Lowry acid. In the Bronsted-Lowry model, the OH- ion is the active species in this reaction it accepts an H+ ion to form a covalent bond. In the Lewis model, the H+ ion is the active species it accepts a pair of electrons from the OH- ion to form a covalent bond. NOTE: All single-hydrogen acids are monoprotic but not all monoprotic acids contain only a single hydrogen. Because only one hydrogen is released, the pH calculation for a monoprotic acid is fairly straightforward and predictable. A monoprotic base will only accept a single hydrogen atom. OTHER EXAMPLES: Polyprotic acids are specific acids that are capable of losing more than a single proton per molecule in acid-base reactions. In other words, these are acids that have more than one ionizable H+ atom per molecule. Protons are lost through several stages (one at each stage), with the first proton being the fastest and most easily lost. OTHER EXAMPLES: Acid Name Formula Carbonic acid H2CO3 Hydrogen Sulfide H2S Oxalic acid H2C2O4 Malonic Acid H2C3H2O4 H2SO4(l) + H2O(l) H3o+(aq) + HSO4-(aq) acid base acid base NH3(g) + H2O(l) NH4+(aq) + OH-(aq) base acid acid base HBr(aq) + NaOH(aq) H2o+(l) + NaBr(aq) acid base water salt