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What happens when an acid neutralizes a base?
an ionic complound called a salt is formed
Salt solutions can be what?
neutral, acidic, or basic, depending on the acid base properties of the constituent cations and anions
What are the ruls for solution
- strong acid + strong base--> neutral solution
- strong acid + weak base --> acidic solution
- weak acid + strong base --> basic solution
Salts such as NaCl that are derived fro a strong base (NaOH) and a strong acid (HCl)) yield __ solutionsbecause what?
- neutral solutons
- neither the cation nor the anio reacts appreciably with water to produce H3O+ or OH- ions
As a __ of a strong acid, Cl- has no tendency to make __. What about Na+
- conjugate base
- the solution basic by picking up a proton from water
- the same thing; it won't transfer a proton to a solvent
Which ions don't react appreciably with water to produce either H3O+ or OH-?
Salts that contain only these ions give neutral solutions in pure water
- Cations from strong bases:
- - alkali metal cations of groups 1A (Li+, Na+, K+)
- - alkaline earth cations of gorup 2A (Mg2+, Ca2+, Sr2+, Ba2+) except Be2+
- Anions from strong monoprotic acids:
- - Cl-, Br-, I-, No3-, ClO4-
Salts like NH4Cl that are derived from a weak base (NH3) and a strong acid (HCl) produce __. In such a case, teh anion is neither acid nor a base, but the cation is a __.
- acidic solutoins
- weak acid
Although the reaction of a cation or anion of a salt with water to produce H3O+ or OH- ions is sometimes called a __, there is no fundamental difernece between a __ and any other __.
- salt hydrolysis reaction x2
- Bronsted-Lowry acid-base reaction
Another type of acidic action is the hydrated cation of a small __.
highly charged metal ion
All metal ions exist in aqeous soluton as __, but the acidity of these cations vries greatly dependeing on the __.
- hydrated cations
- charge and size of the unhydrated metal ion
In general, the acidity of hydrated main-groups cations does what?
increases from left to right in the periodic table as the metal ion charge increases and teh metal ion size decreases
Transition metal cations, such as Zn2+, Cr3+, and Fe3+ also give __.
Salts such as NaCN that are derived from a strong base (NaOH) and a weak acid (HCN) yield __. In this case, the cation is __ and the anion is __.
- basic solutions
- neither an acid nor a base
- anion is a weak base
If there are both a weak acid and aweak base, what will the pH depend on?
the relative acid strength of the cation adn base strength of the anion
What are the three posible cases for salts that contain acidic cations and basic anions?
Ka > kb = solution contains an excess of H3O+ ions
- ka< kb= solution has alot of OH- ions
- ka = kb: approximately equal concentratiosn
Why is one acid stronger than another?
the extent of dissociation of an acid HA is determined by the strenght and the polarity of the HA bond
strength of the HA bond
the enthalpy required to dissociatie HA into an H atom and an A atom
The polarity of the HA bond increases with what?
increase in the electronegativity of A and is related to the ease of electron transfer from an H atom to an A atom to give an H+ cation and an A- anion
In general, the weaker and more polar the HA bond,
the stronger the acid
In general, for binary acids of elements in the same group of the periodic table, the __ is the most important determinant of acidity.
HA bond strength
What happens with the HA bond strength with increasing size of element A down a group?
generally decreases; so acidity increases
Periodic trend of bond strength?
it generally decreases and acidity increases going down
For binary acids of elements in the same ROW of the periodic table, the changes in the HA bond strength are what?
smaller and hte polarity of hte HA bond is teh most imprtant determinant of acid strength
The strength of binary acids of hte second row elements, for example, __ as electronegativity of A increases
For oxoacids that contain the same number of OH groups and the same number of O atoms, what happens to acid strength?
increaes as the electronegativity of Y increases
As the halogen becomes more electronegative, an increasing amount of __ shifts from the OH bond toward the __, weakening the __ and increasing its __. As a result, the proton is more easily transferred to a solvent water mlecule, and so the __ increases.
- electorn density
- O-H bond
- acid strength
For oxoacids that contain the same atom Y but differnet numbers of oxygen atoms, what happens to acid strength?
increases as the oxidation number of Y increases
Another factor that affects the acid strength of oxoacids is __
As the stbaility of the anion increases, the corresponding acid has a __
- the relative stability of corresponding oxoanions
- greater tendency to dissociate
When a base accepts a proton, it does so by
sharing a lone pair of electrions with the proton to form a new coalent bond
In Lewis reactions, the proton behaves as an __.
electron-pair acceptor and the ammonia moelcule as an electron pair donor
electron pair aacceptr
electron pair donor