Part A:

Unknown Acid use 1gram and mix with 120 mL of distilled water
Determine the concentration of the acid by titrating with 0.0998 M of NaOH

Concentration of NaOH= 0.0998M
Volume of NaOH= 3.5 mL
# moles of NaOH=
Initial Concentration of Weak Acid-

Show Calculation of Ka and pKa of weak acid:

Part B:
pH of solution – 3.22 ( determined by using a pH meter to find pH of weak acid)
Show calculation of Ka and pKa of weak acid

moles NaOH = M x L = ??

IF (and that's a big if) moles acid = moles NaOH, then concn acid = mole/0.120 L. I don't think you have enough information to calculate Ka and pKa of the weak acid. Is the 1 g pure acid or is it a sample mixture? Does part B go with part A using the same data? I don't get part B at all

Yes they go together

Part A:

To determine the concentration of the unknown acid, we can use a process called titration. Titration involves reacting a known concentration of a solution (in this case, the NaOH solution) with the unknown concentration of the acid to determine its concentration.

First, let's find the number of moles of NaOH used in the titration:
Volume of NaOH = 3.5 mL = 0.0035 L
Concentration of NaOH = 0.0998 M
Number of moles of NaOH = volume (in L) x concentration
= 0.0035 L x 0.0998 M

Next, we need to determine the initial concentration of the weak acid. In a titration, the moles of acid used should equal the moles of base used. Therefore, the number of moles of the weak acid can be calculated by using the balanced chemical equation between the weak acid and NaOH. However, since we don't have the balanced equation or know the stoichiometry, we cannot calculate the exact concentration of the weak acid. Without additional information or data, it is not possible to determine the initial concentration of the weak acid.

To calculate the Ka and pKa of the weak acid, we usually need the concentration of the weak acid and information about its dissociation or ionization in water. Unfortunately, as mentioned above, without the initial concentration or additional information, we cannot calculate the Ka and pKa of the weak acid.

Part B:

To calculate the Ka and pKa of the weak acid based on the pH of the solution, we need to use the Henderson-Hasselbalch equation, which relates the pH, pKa, and the concentrations of the weak acid and its conjugate base:

pH = pKa + log([A-]/[HA])

In this case, since we don't know the exact concentration of the weak acid or its conjugate base, we cannot directly calculate the Ka and pKa. We would need additional information like the concentration of the weak acid or its conjugate base to solve for these values.

Therefore, without more information, it is not possible to calculate the Ka and pKa of the weak acid in Part B.