What is the Difference Between Total Acidity and Titratable Acidity?

The difference between total acidity and titratable acidity lies in the fact that total acidity refers to the sum of all organic acid anions in a solution, while titratable acidity measures the total available hydrogen ions in solution. Here are the key differences between the two:

• Total Acidity: This is a measure of the total number of hydrogen ions that occur in a substance. It includes both the dissociated and undissociated forms of each acid.
• Titratable Acidity: This is a measure of the amount of strong base required to titrate the sample. It is the number of protons recovered during a titration with a strong base to a specified endpoint.

The titratable acidity is always less than the total acidity because not all of the hydrogen ions expected from the acids are found during the determination of titratable acidity. There is no direct or predictable relationship between pH (a measure of the concentration of free hydrogen ions in solution) and titratable acidity, as both can vary independently.

Comparative Table: Total Acidity vs Titratable Acidity

Total acidity and titratable acidity are two important factors in the analysis of different samples. The key difference between total acidity and titratable acidity is that total acidity refers to the sum of titratable and non-titratable acidity, while titratable acidity refers to the volatile acid content of a sample that can be titrated. Here is a summary of the difference between total acidity and titratable acidity in tabular form:

Please note that titratable acidity is commonly used to determine the total acidity of a sample, as it is easier to measure.