Explain the difference between mass and volume.
How to choose a buffer: the pKa of the buffer should match the pH you desire to buffer at. Sample problem: You mix 5 ml of 0.1 M NaOH with 20 ml of 0.1 M of a weak acid, HA, with a Ka of 10 . What is the resulting pH of this solution This is a limiting reagents problem. The reaction will go to completion because strong bases such as NaOH react until all is used up. Convert everything to mmol by multiplying molarity by mL. You will get 0.5 mmol NaOH and 2 mmol HA. Use an ICE table. Your limiting reagent is NaOH, as there are fewer moles of it present and species react in a 1:1 mole ratio. Your final concentration of HA is 2mmol-0.5mmol=1.5mmol. Your final concentration of NaA (which will dissolve in solution and be present at A ) is 0.5 mmol. Now, ask yourself: Do I have a buffer in