[Arkcon]

No.  Don't think of it as atoms.  Chemistry has only barely reached the point when pick up one molecule, and react it with one other.  Think of it as groups.  What unit do we use to describe groups?  You have a hint in that you have to use the molarity.

[dirknathan]

A mole.  sorry, I know it isn't an atom, but I find my self visualizing the number.  which is still incorrect.

I've gotten the mole down, I know the basic of the titration problem.  I've done plenty where it need the molarity and already offers the volume.  But, this change has thrown me off.  This is one of the problems that is assigned every week where our proffesor just happens to not cover.  I want to learn!  Don't confuse that idea.  You are telling me things I have written down.  It's tedious to type it out on here.  Especially since it is my brain trying to unscramble this issue.

I have done several calculations, but I don't know how to involve the molarity of Ba(OH)₂

[Arkcon]

Great.  You've figured out that the balanced chemical equation relates moles of the reactants and products.  Now, you've been given molarity, do you know how to relate that with moles?  Hint: You'll need another part, which fortunately, you've been given for both  barium hydroxide solution and nitric acid.

[dirknathan]

Got it.  16.8mL.

Thanks for the guidance.