Titration of Phosphoric Acid with NaOH: Understanding the Acid-Base Ratio

Understanding the Acid-Base Ratio in Phosphoric Acid Titration

When conducting a titration of phosphoric acid with NaOH, it is essential to understand the ratio of acid to base for accurate calculations. In this case, the correct ratio is 1 mol phosphoric acid : 2 mol NaOH. This ratio is determined by the chemical properties of phosphoric acid, which is a polyprotic acid.

Polyprotic acids are acids that can donate more than one proton. In the case of phosphoric acid (H3PO4), it has three ionizable hydrogen atoms. This means that each molecule of phosphoric acid can donate up to three protons in a stepwise manner.

During the titration process with NaOH, each mole of phosphoric acid requires two moles of NaOH to fully neutralize it. This is because phosphoric acid has multiple ionizable hydrogen atoms that react with the base.

By understanding this acid-base ratio of 1:2, chemists can accurately calculate the amount of NaOH needed to neutralize a given amount of phosphoric acid. This knowledge is crucial in quantitative analysis and determining the concentration of phosphoric acid in a solution.

Overall, the 1 mol phosphoric acid : 2 mol NaOH ratio is fundamental in the titration of phosphoric acid with NaOH and plays a key role in achieving precise and reliable results in analytical chemistry.