In your lab you are studying aspirin and its acid/base properties. You find that a 1.00 L of a 0.500 M solution of aspirin has a pH of 1.86. You are interested in learning about the % dissociation in

Question:

In your lab, you are studying aspirin and its acid/base properties. You find that a 1.00 L of a 0.500 M solution of aspirin has a pH of 1.86. You are interested in learning about the % dissociation in a buffered solution of aspirin, so you make a new 1.00 L solution containing 0.500 moles of aspirin and 0.45 moles of the sodium salt of aspirin. What will the % dissociation be in this new buffered solution? Give your answer to three decimal places.

Henderson-Hasselbalch Equation:

The Henderson-Hasselbalch equation is a useful equation to estimate the pH of a buffer solution by using the {eq}pK_a{/eq} of the weak acid and the concentrations of the weak acid and conjugate base present in the solution.

{eq}pH = pK_a + log \frac {[A^-]}{[HA]}{/eq}