3.1.8 pH curves

chem whatarethemechanismsofchemicalchange

Reactivity 3.1.8 - pH curves for neutralisation reactions involve strong acids and bases have characteristic shapes and features

generation from a titration

acid-base titration is a quantitative technique.

the reaction between an acid and a base takes place in the flask until the equivalence point or stoichiometric point is reached, when the acid and base are present in ratio where both are exactly neutralised.

plotting the against the volume of titrant added, a non-linear curve is produced (if using a meter continuously)

a big jump in is found in most titrations at equivalence, known as the point of inflection. the equivalence point is determined as being halfway up the jump

the equivalence point can also be determined using an acid-base indicator

curve of strong acid and strong base

• full dissociation is assumed
• as the titrant is added, neutralisation occurs while excess titrand remains
• as volume changes during addition, this must be taken into account in determining the concentration