End point VS equivalence point? (1 Viewer)

[fatassmcfat]

OK i know equivalence point is when base moles = acid moles (not necessarily at ph 7), and end point is when indicator changes colour
But my school pracs we always use phenolphtalein which changes at 8.2ish, although diff equations would have diff equivalence points where they neutralise right?

So How do you know the equivalence point is actually matching up with the end point? Do you just assume they are the same thing?
THANKS

 

[someth1ng]

Ideally, the indicator you choose to use should start changing colour at the equivalence point. In reality, you can only get as close as possible and so, you have the end point.

Typically, it's not a big problem because the amount of acid/base difference from a pH of 7-9 is quite small due to the logarithmic scale.