Question

how do I find the equivalance point and half-equivalance point of a titration curve? I have reasearched around found the equations but cannot locate a good example with a hypothetical situation. I am taking an online course and do not have good access to my instructor. If you have a good example, please share! I am doing titration on citric acid in orange juice and sports drinks.

Thank you!

Answer 1

We titrate weak acid like citric acid with strong base like NaOH , we measure pH after addition of every 1ml base n and we plot pH vs volume of base added.

Equivalence point is where acid moles = base moles .  

we get Moles from formula Moles = Molarity x Volume used in Liters , We will have data of Molarities of both acids . We titrate for fixed volume of acid , we add volume of base such that M x V of acid = M x V of base

This is point of equivalence point . We measure pH at this point. Now at half of volume of base used we find pH , we call it as pH at half equivalence point . PH at half equiavelence is pka of weak acid