College Chemistry II: Ch 17

common ion effect

when a weak electrolyte and strong electrolyte having a ion in common is present in the solution the weak electrolyte ionizes less than usual

buffers

solutions of a weak conjugate acid and its base pair

pH changes (even when strong acid or base is added)

what are buffers resistant to

7.4

what is the pH of human blood

it contains both acid and base to neutralize the effect of added H+ and OH- ions

how do buffers resist pH changes

pH= pka + log[base]/[acid]

henderson hasselbach equation

buffer capacity

the amount of acid or base a buffer can neutralize without appreciable change in pH

pH range

range of pH values over which a buffer system works effectively

0.5 to 1 change in pH

what is the change in pH that tells that a buffer capacity has been reached

more than 10x the other component

if the concentration of the component in the buffer is more than ______x the other component in the buffer buffering capacity is poor

titration

technique where a known concentration of base (or acid) is slowing added to a solution of acid (or base).

indicator

this is used in a titration to indicate the point where stoichiometrically equal quantities of acid and base are brought together (at EQ point)

equivalence point

point at which the stoichiometric amount of acid equals the amount of base

7

what is the pH of the EQ point in a titration of a strong acid with a strong base

titration of a strong acid with a strong base

what type of titration has a pH vs mL NaOH graph with an upward slope (starts slow, grows exponentially, levels out)

titration of a weak acid with a strong base

what type of titration has a pH vs mL NaOH graph with an upward slope and pH changes near the EQ point are more subtle

ph>7

what is the pH of the EQ point on a titration graph of titration of a weak acid with a strong base

titration of weak base with strong acid

what type of titration has a pH vs mL NaOH graph with a downward slope and doesnt use phenolphthalein as an indicator

Titrations of Polyprotic acids

what type of titration has a pH vs mL NaOH graph with an upward slope and EQ point for each dissociation (so multiple EQ points)

solubility product

defined as the product of concentration of the ions involved in the equilibrium each raised to the power of its coefficient in the equilibrium equation

Ksp

solubility product

-common ion effect

-pH

-complex ions

-amphoterism

what are 4 factors that effect solubility

the equilibrium will shift to the left and the solubility of salt will decrease

if one of the ions in a solution equilibrium is already dissolved in the solution, what will happen to the equilibrium and solubility

more soluble

if a substance has a basic anion, it will be __________ (more or less) soluble in an acidic solution

complex ion

an assemblage of a metal ion and Lewis bases bonded to it

Kf

equillibrium constant for complex ions

size of Kf

what does the stability of complex ions depend on

strong acids and bases

amphoteric metal oxides and hydroxides are soluble in what bc they can act as either acids or bases

Q=Ksp

what relationship of Q and Ksp shows that the system is in equllibrium and that it is saturated

Q

what relationship of Q and Ksp shows that more solid can dissolve until equilibrium is reached

Q>Ksp

what relationship of Q and Ksp shows that the salt will precipitate until equilibrium is reached