Weak Acids and Bases, pH, and pKa Flashcards
1
Q
what is a weak acid?
A
a molecule that loses a proton
2
Q
what are the formulas for the Autoionization of Water?
A
H₂O ⇌ H₃O⁺ + OH⁻
Kw = 10⁻¹⁴
pH = 7 in pure water
3
Q
what is a weak base?
A
a molecule that gains a proton
4
Q
what is the formula for ph?
A
pH= -log[H⁺]
5
Q
what is the Henderson-Hasselbalch equaiton? what is the pH and the pKa like?
A
pH = pKa + log([A⁻]/[HA])
50% protonation at pH = pKa.
5
Q
what does pKa indicate? what does a low pKa mean?
A
acid strength, lower = stronger
5
Q
what are Polyprotic Acids? what are their pKa values like?
A
acids that can donate multiple protons
Multiple pKa values.
6
Q
what affects the Charge States of Biomolecules?
A
pH affects charge of functional groups
7
Q
how are Environment and pKa related?
A
pKa changes with environment, affecting reactivity.
