How to make a buffer?
So I have to make a 0.02 M Sodium Phosphate buffer @ pH of 7, easy enough I use monosodium and disodium phosphate as the acid and base, I used the henderson hasselbach equation. But now I have to make a 0.02 M Sodium phosphate buffer with 1 M NaCl?? I'm not sure what this means. When I asked the professor, she said that we have to have these two different solutions in one beaker and have the pH at 7. I need .75 ml of this solution. How can I accomplish this?