[Hello08]

A buffer solution was made by dissolving 19.6 g of Tris base in 280 mL of water and 12 mL of 8 M HCl. The mixture was diluted to a final volume of 500 mL. What is the final pH?
MW of Tris is 121.1 g/mol.


What's throwing me off is the final volume. Also, I was under the impression that you could only use Henderson-Hasselbach equation for Weak Acids and Bases..
Please help. Thank you!

[AWK]

TRIS is a base, HCl is an acid. Can they exist independently in the same solution?
Calculate molar concentration of TRIS and TRIS.HCl in the final volume.