Chapter 19

BASE/ACID

when the processes of dissolution and precipitation reach equilibrium when there is a SMALL concentration of ions

when the processes of dissolution and precipitation reach equilibrium when there is a substantial concentration of ions

is one where a solution is in equilibrium with the solid form of its solute

that very little salt will dissolve; aka that the equilibrium concentrations of hte ions are very small

• show whether a precipitate will form or not:
• if Q < Ksp, the the solution is unsaturated (b/c more ions could enter solution); no precipitate will form
• if Q > Ksp, the solution is super saturated and a precipitation will take place
• if Q = K, then the solution is saturated and ....

• reaction products do NOT influce pH! aka the conjugates of the acid and base
• -pH of 7 when equal amounts have reacted

if you are starting with an acid dissociating but are then given a certain concentration of it's conjugate base, you can then use the acids Ka to find Kb at room temperature, then find the pH of the base if you dissolve it in water, set up eq. ratio, calculate concentration of OH- etc. etc.

-after the equivalence point, the weak acid makes NO difference (don't even have to account for it as the limiting reagent); the solution is super basic so all you have to do is find the concentration of basic titrant = [OH-] to find the pH

• -prior to eq. point the solution is a weak base with some weak conjugate acid present so that an equilibium calculation is required
• -at the equivalence pointall original weak base and strong acid titrant have reacted but conj. weak acid is present (so you need eq. calculation)
• -after equivalence point all that needs to be taken into account is excess strong acid