Buffer Q&A:

Why do we care about buffers?

• It will keep pH constant upon adding acid or base

What do we need in a buffer?

•  a weak acid ($HA$) and its conjugate base ($A^-$)
  • if we add a base, it will react with the acid
  • if we add an acid, it will react with the base

You might ask, “can any buffer work?”

• the desired pH is +/-1 from the buffer $pK_a$

When is a buffer no longer a buffer?

• When you use up one entire speicies

What unit should I work in when I am using buffers?

• MOLES

Things to consider when making a buffer:

• pH +/- 1 from $pK_a$
• What materials you have available (you can make a buffer multiple ways)
  • option 1: 2 solids ($[HA]$ and $[A^-]$)
  • option 2: 1 solid and 1 solution ($[HA]$ solid & $[A^-]$ solution)
  • option 3: 1 solid and 1 solution ($[HA]$ solution & $[A^-]$ solid)
• use Henderson Hasslebach Equation (in pH & pOH)