Flashcards in General Chemistry- Acids and Bases Deck (165)
What is an Arrehnius Acid?
An acid will dissociate to form an excess of H+ in solution
What is an Arrhenius base?
A base that will dissociate to form an excess of OH- in solution
Arrhenius acids and bases behavior is limited to what?
Limited to aqueous acids and bases
How are Arrhenius acids and bases identified?
Acids contain H at the beginning of their formula (HCl, HNO3, H2SO4) and bases contain OH at the end of their formula (NaOH, Ca(OH)2, Fe(OH)3)
What is more a inclusive definition of acids and bases compared to Arrhenius?
A Bronsted-Lowry acid: A species that donates hydrogen ions (H+)
A Bronsted-Lowry base: a species that accepts them.
What is the advantage of the Bronsted-Lowry definition over the Arrhenius definition?
It is not limited to aqueous solutions.
What are examples of Bronsted-Lowry bases?
OH-, NH3, and F-
Because each has the ability to accept a hydrogen ion.
Is water an acid? Based on the Arrhenius definition?
No, it does not produce an excess of H+ in solution
Is water an acid? Based on the Bronsted-Lowry definition?
Yes, because it is able to donate a proton to other species.
Which definition will most likely be used on the MCAT when dealing with acids and bases?
The Bronsted- Lowry
Bronsted-Lowry acids and bases always, what? Why?
Occur in pairs because the definitions require the transfer of a proton from the acid to the base
What are conjugate acid-base pairs?
Bronsted-Lowry acids and bases
What is a Lewis acid?
An electron pair acceptor.
What is a lewis base?
An electron pair donor
What are the other names for Lewis acid base chemistry?
Coordinate covalent bond formation,
Complex ion formation
The underlying idea is that one species pushes a lone pair to form a bond with another
What is the difference between the Lewis definition and the Bronsted-Lowry definition?
Bronsted-Lowry acids and bases, we follow the exchange of the hydrogen ion (H+), which is essentially a naked proton, In the Lewis definion, the focus of the reaction is no longer on the proton, but instead the electrons forming the coordinate covalent bond. This can be seen using curved arrows.
Which acid-base definition is the most inclusive?
Can all Lewis acids and bases be Bronsted-Lowry? Or Arrhenius?
Lewis definition encompasses some species not included in Bronsted-Lowry, and Arrhenius. Every Arrhenius acid is a Bronsted-Lowry acid, and Every Bronsted-Lowry is a Lewis
When are Lewis acids usually used?
In organic chemistry reaction, Lewis acids are usually catalysts.
What's an amphoteric species?
A species that reacts like an acid in a basic environment and like a bse in an acidic environment.
What is the most common amphoteric species on the MCAT?
Water is the most common example
When a water reacts with a base, how does it behave? Acid?
As an acid:
H2O + B HB + OH
In acid, it acts as a base:
HA + H2O H3O+ + A-
When a polyvalent acid partially dissociates, what does it become?
What is an example of a partially dissociated conjugate base of a polyvalent acid?
HSO4- can either gain a proton to form H2SO4 or lose a proton to form SO4 2-
What are also examples of amphoteric?
The hydroxides of certain metals (Al, Zn, Pb, and Cr)
Species that can act as both oxidizing and reducing agents are often considered to be amphoteric as well because of accepting or donating electron pairs, they act as Lewis acids or bases.
What are complex amphoteric molecules?
Amino acids that are a zwitterion intermediate with both cationic and anionic character.
Acids formed from anions with the name that end with -ide change to what?
Have the prefix hydro- and ending in -ic
What are acids formed from oxyanions called?
If the anion ends in -ite (less oxygen), then the acid will end, how?
With -ic acid