Acids And Bases Flashcards
What is a monobasic acid?
1H+ ion can be replaced per molecule in an acid-base reaction.
What is a dibasic acid?
Has 2 protons replaced when they react with bases.
Metal + acid = ?
Salt + H2
What is a neutralisation reaction?
When one mole of water is formed from the reaction of an acid and a base.
What are Bronsted - Lowry acids?
Proton donors
What are Bronsted - Lowry bases?
Proton acceptors
What is a conjugate acid - base pair?
2 species that differ by a H+
What is pH a measure of?
How many H+ ions are present in the solution (concentration)
How do you work out the pH?
-log [H+(aq)]
How do you work out [H+] using pH?
10^-pH
What are strong acids?
Good proton donors
In aqueous solution, they dissociate completely to form ions. HA(aq) – > H+(aq) + A- (aq)
What are weak acids?
Poor proton donors
They partially dissociate into ions when in solution
HA(aq) < – > H+(aq) + A-(aq)
What is Ka?
Acid dissociation constant
( [H+(aq)] X [A-(aq)] ) / [HA(aq)]
What is shown by the Ka value?
The extent of the dissociation of an acid
What is shown by a larger Ka value?
The larger value of Ka, the further the equilibrium is to the right, so the stronger the acid strength.
What are the units of Ka?
moldm-^3
How do you work out pKa from Ka?
-log Ka
What does a large pKa value show?
A weak acid
What is Kw?
The ionic product of water
Kw = [H+(aq)] X [OH-(aq)]
What is the value of Kw under standard conditions?
10^-14 mol^2 dm ^-6
What is the value of pKw under standard conditions?
14 (-log of Kw)
When do you use Kw?
Strong bases
What are weak bases?
They partially dissociate into ions in solution.
They are in equilibrium with their ions in solution.
