posted by student .
If I add 3 mL of 1 M NaOH to a buffered solution, will I still have a valid buffer?
Perhaps yes. Perhaps no. It depends upon the kind of buffer, its concentration, and the pKa value.
the buffer is HEPES, 0.1 M concentration, pka= 7.55
How much buffer do you have? And what is the pH? 50 mL is not enough to still have a buffer after adding the NaOH to a buffer of pH = 7.55. 100 mL of the buffer with a pH = 7.55 would give a pH = 6.94 after adding the NaOH. If you need additional information, please repost at the top of the board.
yes, but it wont be as effective with bases. It should work just as well, if not better, for buffering acids.