Chapter 14 Flashcards
Arrhenius Model acids
release hydrogen ions when placed in water
The Arrhenius Model applies only to?
aqueous solutions and allows for only one type of base
Arrhenius Model bases
release hydroxide ions when placed in an aqueous solution
Bronsted-Lowry model acids
proton donors (hydrogen ions)
Bronsted-Lowry model bases
proton acceptors (accepts hydrogen ions)
Conjugate acids
what the base becomes on the product side of a reaction when the base has accepted the proton.
Conjugate base
what the acid becomes on the product side of the reaction when the acid has donated its proton.
acid dissociation constant refers to?
the dissociation or ionization of an acid.
In the dissociation what is not included and why?
water because in dilute solutions the concentration of water is high and changes very little.
For strong acids the equilibrium lies so far to?
the right that the acid cannot be accurately measured and cannot calculate of Kₐ.
Strong acids
acids with a large Kₐ value
strong acids equilibrium lies to?
the right
a strong acid will yield a?
weak conjugate base (low proton affinity)
Common strong acids
HCl, H2SO4, H3PO4
With strong acids we assume?
they undergo complete dissociation so very little of the original strong acid is left.
Weak acid
acids that do not ionize/dissociate completely with a small Ka value
Weak acids will yield a?
strong conjugate bases (high proton affinity)
in weak acids equilibrium lies?
to the left
In weak acids, most of the acid remains?
in an unionized state in solution
If given a Kₐ value, the acid is?
weak
Monoprotic
1 acidic proton
Diprotic
2 acidic donors
Triprotic
3 acidic donors
Oxyacids
acids in which the acidic proton is attached to an oxygen atom
Organic acids
acids containing the middle acidic carboxyl group
Organic acids are generally?
weak acids with equilibrium to the left
Water can be both a _______ because ________?
acid and base because it self-ionizes
Ion product constant
a dissociation constant that we use whenever we are working with an acid/base/or water
Water is our baseline for any pH situation because?
the pH is 7 due to equilibrium between the Hydrogen and Hydroxide ion concentration
What is typically temperature we measure ion-product constant at?
25 degrees Celsius
Amphoteric
able to react both as a base and as an acid
pH+ and pOH- adds to?
1.0 x 10^-14
From an ion point of view neutral solutions are at equilibrium with?
an equal concentration of Hydrogen and Hydroxide Ions
acids have a greater?
Hydrogen ion concentration
bases have a greater?
Hydroxide ion concentration or an absence of hydrogen ions
Why do bases have an absence of hydrogen ions?
the base has accepted them and removed them from solution
Acids have more hydrogen ions than water so the pH is?
less than 7
Bases have an absence of Hydrogen ions so the pH is?
greater than 7
Each change in pH is a _____ magnitude in each direction.
x10
Measurement of the strength of an acid is based on?
-identity of the acid
-If Kₐ is given
Increase in temperature, causes?
increase in Kw
What is Kw at 25 degrees Celsius?
1.0 x 10-14
At high concentrations of strong acids, the?
auto ionization of water is negligible
the auto ionization of water
a proton is transferred from one water molecule to another to produce a hydronium ion and hydroxide ion,
For strong acids, the assumption we always make is?
the acid has completely ionized.
Weak acids form?
strong conjugate bases
If % dissociation is above 5% we should use?
quadratic formula
% dissociation increases as _____?
acid is diluted
Strong base examples
-group 1 metal hydroxids
-group 2 metal hydroxides
group 2 metal hydroxides are?
less soluble than group 1, allowing them to be used as antacids.
group 2 metal hydroxides can be used as?
antacids
antacids
neutralize the acid in your stomach to relieve indigestion and heartburn
weak bases
-ammoia and other covalent bases
-compounds that have low Kb values
base dissociation constant symbol
Kb
acid dissociation constant symbol
Ka
polyprotic acid
An acid that contains more than one acidic hydrogen atom
In polyprotic acids they can only lose?
one hydrogen atom per round
Polyprotic acids example.
Sulfuric (1): H₂SO₄
Sulfuric (2): HSO₄
Polyprotic acids have no effect on?
speed or strength
In polyprotic acids, no matter what use?
the first reaction as the base for pH
Why do we use the first reaction from polyprotic acids?
where the majority of the hydrogens come from.
If a salt is made of the cation of a strong base and the anion of a strong acid then?
it will have no effect on pH when dissolved in water because it is weak
Cations of strong bases
Na⁺, K⁺
Cations of strong bases and anions of strong acids have?
no affinity for hydrogen ions
anions of strong acids
Cl⁻, NO3⁻
In both cases if cation strong base or anion strong acid is present pH?
does not change due to presence of these ions
salts that produce basic solutions
salt whose cation has neutral properties and whose anion is the conjugate base of a weak acids
In salts that produce basic solutions the conjugate base is _____ and comes from where?
strong and from the dissociation of the weak acid.
salts that produce acidic solutions
situation where the cation conjugate acid is from a weak base and anion is neutral.
salts that produce acidic solutions is due to?
the dissociation of a weak base that produces strong conjugate acid ion
Salts that produce acidic solutions are also found when a salt?
dissociates into a highly charged metallic ion such as Al⁺³
In salts that produce acid solutions, the highly charged cation or conjugate acid?
polarizes water and one hydrogen from the water molecule will become H⁺.
Salts with acidic and basic ions (acidic)
If Ka ion greater than Kb ion, the solution will be acidic
Salts with acidic and basic ions (basic)
If Kb ion is greater than Ka ion,the solution will be basic.
Salts with acidic and basic ions (neutral)
If Kb ion is the same as Ka ion, the solution will be neutral.
conjugate acid base pair example
-H2O (base) and H3O (conjugate acid)
-HA (acid) and A (conjugate base)
conjugate acid base pair
consists of two substances related to each other by the donating and accepting of a single proton.
calculation for the pH of a typical weak polyprotic acids is identical to?
a solution of a weak monoprotic acid
sulfuric acid is unique in being?
a strong acid in its first dissociation step and a weak acids in its second step.
If cation reacts and anions does not the salt is?
acidic
If the cation does not react and the anion does the salt is?
basic
for oxyacids an increase in electronegativity does what to acid strength?
increase
for oxyacids an decrease in electronegativity does what to acid strength?
decrease
decrease in bond strength does what to acid strength?
Increase
increase in bond strength does what to acid strength?
decrease
equilibrium favors the side with the?
weak acids and base
