CAP 11 Flashcards
arrhenius acids
produce hydrogen ions (H+) when they dissolve in water
Naming acids
- Hydrogen + Non metals= hydro+ -ic acid
(ex. hydrochloric acid) - Hydrogen and polyatomic ions:
ate becomes -ic acid (chlorate- chloric acid)
ite becomes -ous acid (chlorite- chlorous acid)
HCl
Hydrochloric acid
strong
HBr
Hydrobromic acid
strong
HI
Hydroiodic acid
strong
HCN
Hydrocyanic acid
HNO3
Nitric acid
strong
HNO2
Nitrous acid
weak
H2SO4
Sulfuric acid
strong
H2SO3
Sulfurous acid
H2CO3
Carbonic acid
HC2H302
Acetic acid
weak
H3PO4
Phosphoric acid
weak
H3PO3
Phosphorous acid
HClO3
Chloric acid
HClO2
Chlorous acid
Arrhenius bases
Produce hydroxide ions (OH-) in water
Naming bases
Arrhenius bases are named as hydroxides ex. - NaOH sodium hydroxide - KOH potassium hydroxide -Al(OH)3 aluminium hydroxide
Why arrhenius’ theory is shacky
- cannot explain why substances lacking hydroxide ions are bases ( ex. NH3)
- does not take into account the role of solvent
- does not describe accurately the role of H+ ion state ( does not exist as such in water)
Bronsted-Lowry acids and bases
- an acid is a substance that donates H+
- a base is a substance that accepts H+
Lewis’ acids and bases
- Acids can accept an electron pair
- Lewis bases can donate an electron pair
Conjugate acid-base pairs
In any acid-base reaction there are two conjugate acid-base pairs.
Each pair is related by the loss and gain of one H+
Amphoteric substances
Substances that can act as both acid and bases
ex. water: donates H+ when it reacts with a stronger base, accepts H+ when it reacts with a stronger acid
Strong and weak acids
- Strong acids completely ionizes in aqueous solutions
- Weak acids dissociate only slightly in water to form a few ions in aqueous solution
Strong acids
HI ( hydroiodic
HClO4
Perchloric acid
Strong
HF
Hydrofluoric acid
weak
Diprotic acids
Some acids have 2 H+ that dissociate one at a time
Diprotic acids
Some acids have 2 H+ that dissociate one at a time
Strong bases
- Dissociate completely in water
- Are formed from metals of groups 1A and 2A
include:
LiOH
NaOH
KOH
Ba(OH)2
Sr(OH)2
Weak base
Poor acceptors of H+
Include:
NH3 ( ammonia)
NaOCl ( bleach)
Acid dissociation constant
Is used to quantitatively measure the strength of an acid.
Small: the equilibrium lies to the left
Large: the equilibrium lies to the right
When an acid is strong, it’s Ka is not reported as dissociation is considered complete
Base dissociation constant
The stronger the base, the larger the Kb
Small: equilibrium to the left
Large: equilibrium to the right
Water dissociation constant
Kw= (H3O+) (OH-) Kw= 1.0 x 10^-14
The pH scale
Used to describe the acidity of solutions Has values that usually range from 0 to 14 Acidic < 7 Basic > 7 Neutral= 7 Is a logarithm of the H30+ pH= - log (H3O+) pH decreases as the H3O+ increases
Acids react with
- metals to produce salt and hydrogen gas
- bases to produce a salt and water
A salt
An ionic compound that does not have H+ as the cation or OH- as the anion
Neutralization reaction
An acid reacts with a base to produce salt and water
The salt formed is the anion from the acid and the cation from the base
Antiacids
Substances that:
- are used to neutralize excess stomach acid
- are made of aluminum hydroxide and magnesium hydroxide mixtures
Acid base titration
- Procedure used to determine the concentration of an acid or a base by neutralizing it with a buffer
Indicator
Ex. phenolphthalein
is added to identify the endpoint