Chapter 21 - Buffers and neutralisation Flashcards
what is a buffer solution?
a system that minimises pH changes when small amounts of acid or a base is added
what does a buffer contain?
a weak acid and its conjugate base
in addition of an acid to a buffer solution, which way does equilibrium shift?
to the left
in addition of alkali to a buffer solution, which way does equilibrium shift?
to the right
when the concentration of the weak acid and its conjugate base are equal, what can be said about the pH?
it will be the same as the pKa value of the weak acid and the operation pH is typically over two pH units, centred at the pH of the pKa value
what is the equation for [H+] in a buffer solution?
Ka x [HA] / [A-]
what is the most important buffer solution in the body?
the carbonic acid - hydrogen carbonate system
what is the equivalence point of a titration?
when the volume of one solution reacts exactly with that of the other
what is the end point of a titration?
the indicator contains equal concentrations of HA and A-
