Chemistry Titration: How to Reach a pH of 7.10

How many milliliters of NaOH solution are necessary to reach a pH of 7.10?

Given a solution made with 0.149 moles of phosphoric acid (H3PO4) dissolved in 159ml of solution was titrated with 1.250M KOH, how much NaOH solution is needed to achieve a pH of 7.10?

Answer:

To determine the amount of NaOH needed to reach pH 7.10 in a solution of 0.149 moles phosphoric acid and 1.250 M KOH, one needs to consider that H3PO4 is a triprotic acid, and more in depth calculations involving pKa values and the Henderson-Hasselbalch equation would be required.

Understanding the Chemistry Behind Titration

When conducting a titration in chemistry, it involves determining the concentration of a specific substance in a solution by adding a reagent of known concentration until the reaction reaches equilibrium.

In the case of the given scenario where phosphoric acid (H3PO4) is being titrated with KOH, it's important to consider that phosphoric acid is triprotic, meaning it can donate three protons to a base like KOH in a specific ratio.

Calculating the exact volume of NaOH solution needed to reach a pH of 7.10 involves taking into account the dissociation steps of H3PO4 (with pKa values of 2.12, 7.20, and 12.4) and utilizing the Henderson-Hasselbalch equation for accurate calculations.

By understanding the stoichiometry of the reaction and the specific properties of the acids and bases involved, one can accurately determine the amount of NaOH solution required to achieve the desired pH level in the titration process.