pH changes
20 ml of sodium hydroxide (pH = 14) is reacted with 20 ml of hydrochloric acid (pH = 1).
What is the final pH and why?
Possible answers:
14, something between 7 and 14, 7, something between 7 and 1, 1, "need more information".
Think carefully and logically. There is more to this than you think!
Clue for answers
Many people think (wrongly) that pH is a scale from 1 - 14. They would guess that equal amounts of each extreme would lead to th middle "avergae" value.....WRONG!
Calculate the moles of H+and OH- present and then see what is left over.......
Can't work out the moles of H+and OH-? Think of the definition of pH (pH = -log10[H+]) ...
....and use Kw = [H+][OH-]
More clues later if you need them.
