T12 Acid-base equilibria Flashcards
acids
proton donors, releasing H + ions in water to form hydroxonium ions (H3O+)
bases
proton acceptors
take H+ ions from water molecules in solution to form OH- ions
strong acids /bases
dissociate completely in water
e.g HCl/ NaOH
weak acids/bases
dissociate partially in water
forms an equilibrium lying to the left
conjugate pairs
species linked by the transfer of a proton
conjugate base
species that has lost a proton
conjugate acid
species that has gained a proton
neutralisation reactions
when acids and base react together to form water and a salt.
neutral solution
equal conc of H+ and OH- ions
standard enthalpy change of neutralisation
enthalpy change when solutions of an acid and base react under standard conditions to produce one mole of water.
always negative as is exothermic
weak acid base neutralisation enthalpy
vary as only dissociate partially/reversibly and ions get used up quickly
strong acid base neutralisation enthalpy
no dissociation enthalpy just the reaction of H+ and OH- ions
pH equation
-log10(H+)
pH define
measure of hydrogen ion concentration
monoprotic acids
each mole of acid produces one mole of hydrogen ions
acid conc for strong, monoprotic acids
concentration of H+ ions
how do you find H+ conc from the pH
10 to the negative pH