04/22 Flashcards
what is advanced equilibria
it is equilibria that involves more than a single reaction where the concentrations of the products or reactants are reliant on each other
what is the difference between a weak acid and a strong acid
a weak acid partially dissociates, some of the HX is still present in solution
a strong acid dissociates completely, none of the HX is present in the solution
if we have a small ka, what does it mean?
it means our acid is very weak and not good at making H30+
if we have a large ka, what does it mean?
it means our acid is very strong and good at making H3O+
what is the difference between weak bases and strong bases
strong bases dissociate completely to give OH
weak bases do not dissociate completely (Some XOH is left)
what is true about conjugate acid base pairs and equilibrium constants
ka*kb=kw
if we know one we can find the other
what is kw at 25 C
1x10^-14
if our dissociative ions form strong acids or bases when dissolved in water, would that actually happen and contribute to the PH?
no, it is unstable to form a strong acid or base and equilibrium favors the formation of weak acids/bases
when are ions recognizable as conjugate acids or bases?
when they form weak acids or bases in water
conjugate bases of weak acids form what types of solutions
basic solutions
conjugate acids of weak bases form what types of solutions
acidic solutions
how will NaBr affect the PH when dissolved in water
neutral no change
Na is the conjugate to a strong base
Br is the conjugate to a strong acid
how will NH4Cl affect pH when dissolved in water
NH4 is the conjugate acid to a weak base —> acidic
Cl is the conjugate base to a strong acid—> neutral
the pH will be acidic
how will K2HPO4 effect pH
the solution will be basic
K is the conjugate to a strong base, so it is neutral
the HPO4 is the conjugate to a weak acid and forms hydroxide so it will be basic
how will KCH3COO affect PH?
it will be basic
when we add an “inert” salt to a not very soluble salt, what happens to the solubility of the salt
it increases the solubility
why does adding an inert salt increase the solubility?
it increases the ionic strength of a solution which increases the charge on the ionic atmosphere.
The ionic atmosphere decreases the attraction between the ions in the salt (Ca2+ and SO4^2-) which increases the solubility
what interaction is being described by adding ions to a solution with an insoluble salt?
its an electrostatic interaction
what is the ionic atmosphere
it is the region of net positive or negative charge around a cation or anion in a solution
in a solution with an inert salt, an anion is surrounded by
excess cations
in a solution with an inert salt, a cation is surrounded by
excess anions
when you have a greater ionic strength, what happens to the charge in the atmosphere
it is higher
what is ionic strength
it is u and is a measure of the total concentration of ions in a solution
if you have a highly charged ion, what is the influence on u
it has a higher influence lol
why do we not include H30 and Oh in the ion strength calculation
if we have a neautral solution, they have a negligible affect on the strength
is a solution of CaCl in water, what ions are present and which do we care about
Ca, Cl, H+ and Oh- are in the solution but H and OH are neglible and do not contribute to the ionic strength sufficiently enough to be considered
