We had a lab where the standard solution was potassium hdrogenphthalate. In this we added 3 drops of phenolphtalein indicator and then we ran sodium hydroxide into the solution. We did four different flasks and the final readings for these then were 26.00 cm3, 32.00 cm3, 26.10 cm3 and 29.90 cm3. So, my question is how do I calculate the concentration of the hydrogenphthalate solution and the concentration of the sodium solution.

Thanks on beforehand

Just saw that I forgat to notice that the amount of potassium hydrogenphtalate was 5.12 grams. Also, it was enough with two readings within ± 0,01 cm3

mols KHP = grams/molar mass

mols NaOH = mols KHP
M NaOH = mols NaOH/L NaOH

To calculate the concentration of the hydrogenphthalate solution and the concentration of the sodium hydroxide solution, you need to perform a titration calculation.

Step 1: Balanced Equation
First, let's write the balanced chemical equation for the reaction between potassium hydrogenphthalate and sodium hydroxide:
KHC8H4O4 (aq) + NaOH (aq) → NaKC8H4O4 (aq) + H2O (l)

Step 2: Stoichiometry
Based on the balanced equation, we can see that the mole ratio between potassium hydrogenphthalate and sodium hydroxide is 1:1. This means that the number of moles of potassium hydrogenphthalate reacted is equal to the number of moles of sodium hydroxide added.

Step 3: Calculation
To calculate the concentration of the hydrogenphthalate solution, you can use the following formula:
Concentration (mol/L) = (Volume of Sodium Hydroxide (L) × Molarity of Sodium Hydroxide (mol/L)) / Volume of Hydrogenphthalate (L)

For each flask, calculate the concentration of the hydrogenphthalate solution using the above formula, and take the average of the values obtained from the four flasks.

To calculate the concentration of the sodium hydroxide solution, you need to use the same formula but rearrange it:
Molarity of Sodium Hydroxide (mol/L) = (Concentration of Hydrogenphthalate (mol/L) × Volume of Hydrogenphthalate (L)) / Volume of Sodium Hydroxide (L)

Again, calculate the concentration of the sodium hydroxide solution for each flask and take the average of the values obtained from the four flasks.