Ionic Equilibrium Flashcards
What is the ionic product of water, Kw?
Kw = 10-14 mol2 dm-6 for all aqueous solutions at 25°C
Note: Kw = [H+] [OH-]
Define pH.
It is the negative logarithm to base 10 of hydrogen ion concentration.
pH = -log10 [H+]
pH = 14 - pOH
What are buffer solutions?
They are solutions that resist change in pH upon additions of small amounts of acid of alkali.
What is an acid?
Substance that can donate a proton, H+.
What do you understand by the Bronsted-Lowry theory of acids and bases?
An acid is a substance that can donate a proton to a base while a base is a substance that can accept a proton from an acid.
What is a base?
Substance that can accept a proton, H+.
What are strong acids and bases?
They dissociate completely in water.
How are acidic buffers prepared?
Mixing a weak acid and salt of weak acid and strong base.
Eg. CH3CO2H/CH3CO2Na
What is meant by equivalence point of an acid-base titration?
Point at which stoichiometrically equivalent quantities of acid and base have been added together.
How are alkaline buffers prepared?
Mixing a weak base and salt of weak base and strong acid.
Eg. NH3/NH4Cl
What do you know by strength of an acid?
It is a measure of the extent of the equilibrium which proceeds from left to right.
Define pOH.
It is the negative logarithm to base 10 of hydroxide ion concentration.
pOH = -log10 [OH-]
pH = 14 - pOH
