Topic 18 Flashcards
What is a lewis acid?
Electron pair acceptor
What is a lewis base?
Electron pair donor
What is an electrophile?
A substance that accepts a lone pair of electrons like a lewis acid
What is a nucleophile?
A substance that donates a lone pair of electrons
What is the difference between a BL acid and a lewis acid??
A lewis acid accepts electrons whereas a BL acid donates protons
What is Ka?
The acid dissociation constant
What is Kb?
The base dissociation constant
What is one of the formulas for Ka?
Ka = (H+)2/ HA
What does the magnitude of Ka tell you?
- The extent of dissociation of the acid
- increase in Ka= increase in dissociation = the stronger the acid
What does the magnitude of Kb tell us?
- The magnitude of dissociation of the base
- The higher the Kb the higher the dissociation the stronger the base
What is one of the formulas for Kb?
Kb = (OH)2/HA
What is Kw?
The ionic product constant of water
1X10-14
What is the formula for Kw?
Kw = Ka X Kb Kw = ( H+)(OH-)
Relationship between Ka and pKa?
Ka = 10-pKa pKa = - log ( Ka)
Relationship between Ka and pKa?
Ka = 10-pKa pKa = - log ( Ka)
What happens to the pKA value when Ka is increases?
pKA decreases
Is Kw temperature dependent?
Yes
Write the equations for the dissociation of water
H20 = H+ + OH-
Draw the pH curve for a strong acid strong base reaction
Draw the pH curve for a weak acid and strong base
Draw the pH curve for a strong acid and weak base
What is the equivalence point?
When equivalent amounts of acids and bases have reacted
- and the solution only contains salt and wate
- pH depends on the salt
What is the buffer region?
When small amounts of acid and bases are added whih resists a pH change
What is the half equivalence point?
When half the acid has been neutralised by the base and is converted into salt
