What is the effect of adding acid to a buffer solution?
The buffer resists the change in pH by reacting with the added acid.
What is the effect of adding base to a buffer solution?
The buffer resists the change in pH by reacting with the added base.
What happens to pH as $[H^+]$ increases?
pH decreases (becomes more acidic).
What happens to pOH as $[OH^-]$ increases?
pOH decreases (becomes more basic).
What happens to the pH at half equivalence point?
pH = pKa
What happens to the pH at equivalence point?
The number of moles of acid and base are equal, so the pH depends on the strength of the acid and base.
Define acid.
Substances with a pH less than 7 that donate H+ ions.
Define base.
Substances with a pH greater than 7 that accept H+ ions.
Define pH.
A measure of the concentration of free protons (H+) in a solution.
Define pOH.
A measure of the concentration of hydroxide ions (OH-) in a solution.
Define buffer.
A solution that resists changes in pH when small amounts of acid or base are added, composed of a weak acid/base and its conjugate.
Define $K_a$.
Acid dissociation constant; measures the strength of a weak acid.
Define $K_b$.
Base dissociation constant; measures the strength of a weak base.
Compare strong acids and weak acids.
Strong acids: completely dissociate in water, high $[H^+]$ | Weak acids: partially dissociate, lower $[H^+]$
Compare strong bases and weak bases.
Strong bases: completely dissociate in water, high $[OH^-]$ | Weak bases: partially dissociate, lower $[OH^-]$
Compare pH and pOH.
pH: measures acidity, pH = -log$[H^+]$ | pOH: measures basicity, pOH = -log$[OH^-]$
Compare $K_a$ and $K_b$.
$K_a$: acid dissociation constant, measures acid strength | $K_b$: base dissociation constant, measures base strength
Compare equivalence point and half-equivalence point in a titration.
Equivalence point: acid and base have completely reacted | Half-equivalence point: pH = pKa (weak acid), pOH = pKb (weak base)
