acids and bases Flashcards
State the arrhenius definition
Acids produce hydrogen ions in aq solutions and bases produce hydroxide ions in aq solutions
State the bronsted-lowry definition
An acid is a proton donor and a base is a proton acceptor
According to the bronsted-lowry definition what are acidic protons often attached to
Oxygen
Halogens
Nitrogen atoms
According to the bronsted-lowry definition what do bases need
Lone pair electrons to act as a proton acceptor
Acids and bases occur as what
Acid-base pairs
Base –> conjugate acid
Acid –> conjugate base
What is ka
Acidity constant
Ka = [H+][A-]/[HA]
Describe strong acids
Most of acid is dissociated (ionized, strong electrolyte) Ka = large Equilibrium lies far right [H+]=[HA]initial A- much weaker base than H20
State strong acids
HCl HI HBR HNO3 H2SO4 HClO4
Describe weak acids
Ka = small
Equilibrium lies far left
[H+] < [HA]initial
A- much stronger base than a H2O
State weak acids
HF
CH3COOH (acetic acid)
HCOOH (formic acid)
HOOCCH2CCH2COOHCOOHOH (citric acid)
Describe relationship between acid and base conjugate pairs
Inverse relationship
Strong acid –> doesn’t react as base (spectator)
Weak acid –> weak base
Doesn’t react as acid –> strong base
What is water
Amphoteric
Acts as an acid or base
What is Kw
Ion product constant of water
Kw=[H3O+][HO-] = 1.0x10^-14 @ 25degrees c
What is Kw in neutral
[H30+]=[HO-] = x
Kw=x^2 –> x=1.0x10^-7
What is Kw in acidic
[H30+]>[OH-]
What is Kw in basic
[H30+] IS LESS THAN [OH-]
State relationship between H+ and pH
As [H+] increases pH decreases
As [H+] decreases or [HO-] increases pH increases
State formulas for the pH scale
Kw=[H3O+][HO-] = 1.0x10^-14 pH = -log [H+] pOH = -log [HO-] -logKw = -log [H+]-log[HO-] = 1.0x10^-14 Pkw = pH + pOH / pH+pOH = 14.00 [H+]= 10^-pH [pOH] = 10^-pOH *2 decimal places, 2 sig figs*