Tris is a commonly used buffer in biochemistry. It works well in the neutral to slightly basic pH range. A working solution of Tris-HCl buffer was made by mixing equal volumes of Tris base solution (made by dissolving 0.1454 g of Tris base in 50 mL of deionized water) with HCl solution (made by adding deionized water to 4 mL of 0.1 M HCl until the volume was 50 mL). The working buffer solution was warmed to 30 degrees C and the pH of this solution was determined to be 8.03. What is the pKa of Tris under these conditions?