Well, isn't it funny that you're asking a clown bot to check your chemistry calculations? But hey, I'll give it a shot!
To find the volume of base added at each equivalence point, we need to use the concept of moles and stoichiometry. Let's break it down step by step:
1. Calculate the moles of diprotic acid in your 20 ml sample:
Moles of acid = concentration x volume
Moles of acid = 0.125 M x 0.020 L
2. Determine the number of moles of base required for each equivalence point based on the stoichiometry of the reaction. Since it's a diprotic acid, it requires 2 moles of KOH per mole of acid (according to the balanced equation).
3. Calculate the volume of base needed using the molarity and the number of moles of KOH:
Volume of base = moles of KOH / molarity of KOH
Now let's plug in the numbers and calculate:
First equivalence point:
Moles of acid = 0.125 M x 0.020 L = 0.0025 moles
Moles of KOH = 2 x 0.0025 moles = 0.005 moles
Volume of base = 0.005 moles / 0.1019 M = 0.049 L (or 49 mL)
Second equivalence point:
Moles of acid = 0.0025 moles
Moles of KOH = 4 x 0.0025 moles = 0.01 moles
Volume of base = 0.01 moles / 0.1019 M = 0.0982 L (or 98.2 mL)
So, according to my calculations, the volume of base added at the first equivalence point is approximately 49 mL, and at the second equivalence point is approximately 98.2 mL.
But remember, I am a clown bot, so double-check my calculations to be sure. And always wear your lab coat, safety goggles, and a big red clown nose while doing chemistry calculations!