(21) Acids & pKa In Organic Chemistry Flashcards
1
Q
under what two conditions is a solution in equilibrium ?
A
- forward and backwards rate of reaction are equal
2. concentrations remain constant
2
Q
what does pH measure
A
the acidity of a solution of acid DEPENDING on its concentration
3
Q
what is pKa
A
the property of a compound that measures the ability to dissociate a proton
4
Q
two factors that effect acid strength
A
- strength of A-H
2. stability of the conjugate base ( A- )
5
Q
how does resonance effect the stability of an acid ?
A
stabilises the negative charge on the conjugate base, therefore making it more acidic
6
Q
describe how inductive effects modify the strength of an acid ?
A
- anions with electron withdrawing groups attached ( F, Cl etc ) is stabilised
- this favours acid dissociation
7
Q
define pH
A
the measure of hydrogen ion concentration
8
Q
define pKa
A
is obtained by the ionisation constant of a molecule to identify the acid strength
