Question

Could someone help with the 4th part of this question?

Answer 1

So the first question asks this: Find the number of moles of HA in the 50 ml of 0.01 M acetic acid. I got 0.005M/L as an answer.

The second question asks this: Find the number of moles of NaOH in 1 ml of 0.20 NaOH. I got 0.02 m/L as an answer.

The third question asks to find the pH using the henderson hasselbalch equation after the addition of 1 ml of 0.20 M NaOH. I got 5.36 as an answer.

The fourth question which im having problems with asks this; Find the pH after the addition of 2,3,4,5....24 mls of NaOH. Each time subtracting the number of moles of NaOH added from the number of HA moles you started with and adding it to the number of A-. Once you reached 24, find ph for 24.2 etc. What is the volume that the ph will be equal to the pK.

Answer 2

each mL of NaOH you add will contain a small number of MOLES of NaOH. These moles will neutralize a small portion of the acid. Use the H-H equation for each mL of base added, taking into account the moles of acid used, and the changing concentrations of the reactants and products. It's a lot of bookkeeping work, but it should all work out.