Ch 14 PPT. 1
Card Set Information
Ch 14 PPT. 1
substance that dissociates in water to produce hydrogen ions, H+
HA<--> H+ + A-
a substance that dissociates in water to produce hydroxide ions, OH-
MOH<--> M+ + OH-
sustance that can transfer H+; proton donor
sustance that can accept H+; proton acceptor
Conjugate acid-base pairs
chemical species whose formulas differ only by one hydrogen ion, H+
Due to __ of the H ion, it is actually __ by one or more __.
For our purpose, H+ is equivalent to __.
True or False: H+ does not exist alone as H+
true: as H30+
What is Bronsted Lowry Theory Acid reaction with water?
HA+H2O <--> H3O+ + A-
What is Bronsted Lowry Theory Base reaction with water?
NH3 + H2O <--> OH- + NH4+
Water is what?
aphoteric (amphoprotic): it can act as an acid or as a base and thus can react with itself
How does water react with itself.
This is called the __ of water.
2 H2O <--> H3O+ + OH-
How many water molecules dissociate when reaction with itself?
1 in 10 milllion
With equal concentrations of reactants and products, what will be the direction of reaction?
from stronger to weaker, whether base or acid
an acid that is only partially dissociated in water and is thus a weak electrolyte
electron-pair acceptor; these are generally cations and neutral molecuels with vacant valence orbitals, such as Al3+, Cu2+, H+. BF3
electron-pair donor; these are generally anions and nuetral molecules with available pairs of electrons, such as H2O NH3, O2-
The bond formed between a lewis acid and a lewis base is called a __.
Explain in depth the coordinate bond
when the bond is formed between one species that donates both pairs of electrons and the other donates none
What is the ion-product constant for water
Kw= [H+][OH-]= 1.0 x 10^-14
What is the relation between H+ and OH- in the constant for water
[H3O+]= [OH-]=1.0 x 10-7
What happens if hte concentration of H3O+ goes up or OH- goes up?
the other one will go down to maintain equilibrium
Acidic would be ?
H3O+ > OH-
Neutral would be
H3O+ = OH-
Basic would be
H3O+ < OH-
What is the scale of pH?
What happens when a solution gets more acidic?
pH gets smaller, while the concentration gets bigger
Acidic < 7
The pH of a solution is the __ of hte __.
hydrogen ion concentration
acid base indicator
a substance that changes color in a specifc pH range
What do indicators exhibit?
pH dependent color changes because they are weak acids ahd have different colors in their acid and conjugate base forms
Strong acids and bases
strong electrolytes that are assumed to ionize completely in water
weak acids and bases
are weak electrolytes that ionize only to a limited extent in water
Solutions of weak acids and bases contain __ and __.
If an acid is strong, what
its conjugate base has no measurable strength
__ is the strongest acid that can exist in aqueous solution
__ is the strongest base that can exist in aqueous solution
Acid ionization constant
the equilibrium onstant for the ionization of an acid
a measur eof the strength of an acid
% dissociation= [H+]/[HA0] x 100
Strong acids have __
Percent dissociation of a weak acid does what as it conncentration increases?
higher percent dissociation
decreases as its concentration increases
base ionization constant
the equilibrium constant for the ionization of a base
the ionization of weak bases is treated how?
the same way as the ionization of weak acids
Base dissociation constant
kb= [BH+][OH-]/ [B]
product of Ka and Kb
multiplying out the expressions for Ka and Kb equals Kw
Salts that produce neutral solutions are
those formed from strong acids and strong bases
salts that produce basic solutiosn are those formed from
weak acids and strong bases
salts that produce acidic solutions are those formed from
strong acids and weak bases
Ka > kb
the solution will contain more H30+ ions
Ka < kb
the solution will contain an exces of OH- ions
Ka = Kb
the solution will contain approx. equal concentrations
What is the trend for acid strenghth for H
increases with increasing polarity of HX bond and increasing size of X
Explain the trend of acid strength for H
it increases with incrasing electronegativity