TOPIC 10- ACIDS AND BASES Flashcards
increase hydrogen (π»+ ) concentrations in an aqueous solution.
Acids
increases hydroxide (ππ»-) concentrations in an aqueous solution.
Bases
are proton (π»+) donors.
Acids
are proton (π»+) acceptors.
Bases
When π» receives a proton, it becomes
hydronium (H3O+)
If the acid is strong, use a
forward arrow
If the acid is weak, use a
double-headed arrow
is everything that remains of the acid molecule
after a proton is lost.
conjugate base
is formed when the proton transfers to the base.
conjugate acid
consists of two substances related to
each other by the donating and accepting of a single proton.
conjugate acid-base pair
In strong acids, equilibrium lies far to the
right
In strong acids, almost all the original HA is ____________________ at equilibrium
dissociated (ionized)
Strong acids, yields a
weak conjugate base
an acid whose conjugate base is a much weaker base than water
Strong acids
What are the 7 strong acids?
β π»πΆπ (hydrochloric acid)
β π»πΌ (hydroiodic acid)
β π»π΅π (hydrobromic acid)
β π»ππ (nitric acid) 3
β π»πΆππ (chloric acid) 3
β π»πΆππ (perchloric acid) 4
β π» (sulfuric acid)
In weak acids, equilibrium lies far to the
left
In weak acids, most of the acid placed is still present as __ at equilibrium
HA
has a conjugate base that is a much stronger base than water
Weak Acids
has a higher (π»3O+) and a larger Ka value.
stronger acid
has a lower (π»3O+) and a smaller Ka value.
weaker acid
can act as either an acid or base
amphoteric substance
Example of amphoteric substance
water, π»πΆπ3- and
π»ππ42-
The [H3O+] and [OH-] are
inversely proportional
If [H3O+] > [OH-], the solution is
acidic
If [H3O+] < [OH-], the solution is
basic
If [H3O+] = [OH-], the solution is
neutral
is the negative of the base-10 logarithm of a number.
p-scale
is the negative logarithm of [H3O+] or [OH-]
pH
As [H+] increases, the pH
decreases
The lower the pH and pKa, the __________ the acid
stronger
The extent of ionization of a weak acid can be described in terms of the
degree of ionization or percent ionization.
is the fraction of the ionized acid molecules.
degree of ionization
gives the percentage of ionized molecules.
percent ionization
When you dilute a solution, the percent ionization
increases
If the base is strong, use a
forward arrow
If the base is weak, use a
double-headed arrow.
completely dissociate when dissolved in an aqueous solution
strong bases
strong bases include hydroxides of
Group 1A and 2A elements
have larger πΎ values
strong bases
partially dissociate when dissolved in an aqueous solution and exists in a
solution as mixture of itself and its conjugate acid
Weak Bases
have smaller πΎ values
Weak Bases
will lie to where the weaker acids
and bases are found.
equilibrium of acid-base reaction
If equilibrium lies to the right, πΎa is
large (strong)
If equilibrium lies to the left, πΎa is
small (weak)
The equilibrium concentration of a strong acid/base is always
zero
If πΎw increases as temperature increases, the process is
endothermic
πΎa and Kb are ____________________ to each other.
inversely proportional
The sum of pH and pOH is always
14.00
have a pH greater than 7.00.
Bases
have a pH less than 7.00.
acids
The lower the ππΎ , the ___________ the acid
stronger
The pH of pure water will always be______regardless of temperature.
7.00
is the shift in equilibrium caused by the
addition of a compound having an ion in common with the dissolved
substance.
common ion effect
The presence of a ______________ suppresses the ionization of a weak
acid or a weak base.
common ion
is one that resists a change in its pH when either
hydroxide ions or protons are added.
buffered solution
most important practical example of a buffered solution is our _______, absorbing acids/bases in biological reactions without changing its pH.
blood
is a combination of a weak acid/base and a salt of
that weak acid/base.
buffered solution
________ acids and bases cannot form buffer solutions.
Strong
of a buffered solution represents the amount of
protons or hydroxide ions the buffer can absorb without a significant
change in pH.
buffering capacity
The more concentrated the components of a buffer, the _______ the
buffer capacity.
greater
A buffer has the highest capacity when the component concentrations
are
equal
The most efficient buffering occurs when the [A]/[HA] ratio is close to
1
is the pH range over which the buffer acts effectively.
Buffer range
Steps in Preparing Buffer Solutions
- Choose the conjugate acid-base pair.
- Calculate the ratio of buffer component concentrations.
- Determine the buffer concentration.
- Mix the solution and adjust the pH.
