acids and bases up to %ionization Flashcards
Bronsted acid
a substance that is capable of donating a proton
HA –> H+ + A-
Bronsted base
a substance that is capable of accepting a proton
B + H –> BH+
Conjugate acid
an acid formed when a base accepts a proton
Conjugate base
a base formed when an acid donates a proton
conjugate pair
an acid and a base that only has a proton as their difference. E.G H2SO4 –>
Diprotic and Triprotic
Diprotic is a substance that has 2 donatable protons
Triprotic has 3
Amphoteric
a substance that can behave like an acid or a base depending on what it reacts with
An electrolyte
An electrolyte is any substance that can be dissolved in water to give positive and negative ions
Is water an electrolyte
water is a weak electrolyte because it can autoionize to a small extent
Equilibrium constant
the equilibrium constant explains that at equilibrium, the concs of the forward and reverse reaction remains the same even though the reaction is still occurring
It is represented by K
K= [products] / [reactant]
Kw
This is the equilibrium constant of water.
Kw= [OH-] [H+] = 10^-14 at 25 celsius
At 25 celsius, what is the concentration of water
10^-14 M
At 25 celsius, what is the concentration of H+ in water
10^-7 M
pH
The measure of acidity
pH= -log[H+]
Strong acid and base
A strong acid or base is one that can completely ionize in water
ionization
the breakdown of substances into positive and negative ions
weak acid and base
A weak acid or base does not completely ionize in water. They can approach 100% ionization but can’t reach it.
Relationship between concentration and weak acid/base strength
As the concentration decreases, the strength of the weak acid/base increases. Meaning that at very low concentrations, weak acids/bases can ionize more but not completely. The lowest Ka or Kb is the strongest.
are conjugates weak or strong?
conjugate acids/bases are always weak
examples of strong acids
HCLO4, HCLO3, H2SO4, HNO3, HI, HBR, HCL
examples of weak bases
NaOH, KOH, LiOH, Sr(OH)2, Br(OH)2 etc
Ka
Ka is the strength of the acid. It is also referred to as the acid dissociation constant so the higher Ka is, the stronger the weak acid.
Ka= [products]/[reactant]
how do we determine the pH of a weak acid when Ka is available,
use the ice table
% ionization
It is used to show how much acid was ionized.
% ionization = [ionized acid]/[initial conc] x 100
