Question

you are asked by your research supervisor to prepare 1L of 1M tris-HCL ph 6.8. The molecular weight of tris-HCL is 157.59. how would you change the PH of the solution to 6.8?

Answer 1

The molecular weight of tris is 121.14 g/mole, so dissolve 121.14 g (1 mole) of tris into about 900 mL water, add enough 1 M HCl solution to bring the pH down to 6.8, then add more water to the 1 L mark.