[GregRC]

The question is: A 2.50g portion of tri-protonated Glutamic Acid (FW = 147 g/mol) is dissolved in 0.997 L of distilled, deionized water.  Then 3.0 mLs of 4.0 N NaOH (FW = 40 g/mol) is added.  What is the concentration of the isoelectric form?

I have no idea where to start. I know that I need to use the Henderson Hasselback in some way, but I'm not sure how.

[GregRC]

Anyone have an idea of where to start? A question like this will be on an exam tomorrow, so I will need to understand it.

[Arkcon]

I have no idea where to start. I know that I need to use the Henderson Hasselback in some way, but I'm not sure how.

If this is true (and I have no idea) why not show us an example of the formula with numbers plugged in where you think they should go?  That would be "how you start it." Maybe you have a flash of insight, and maybe someone can give you a hint.  What else can you do, come exam time, if you can't find an example in your class notes or textbook?

[Babcock_Hall]

The terminology of "isoelectric form" is unfamiliar to me.  It might mean the form (protonation state) that has zero net charge.  Can you identify this form?  Also, I would treat this as a limiting reagent problem first.  You have a strong base reacting with a weak acid.  This will go to completion.