In general definition, alkalimetric titration is the same as other types of titration which is the process of measuring the concentration of a solution by creating a reaction between that solution and another solution whose concentration is known in advance. One type of titration is acid-base titration.

Getting to Know the Core of Alkalimetric Titration

Acid-base titration is a method of measuring the concentration of an acid in a solution by means of titrating it with a basic solution whose concentration is known, or vice versa. Then, the acid-base titration itself is further divided into two types, namely:

1. Acidimetric titration

In short, acidimetric titration is a measurement of acid concentration using a standard base solution. When a strong acid is used, a neutral pH is obtained. When the sample used is a strong base, the reaction will take place perfectly.

2. Alkalimetric titration

Alkalimetry is taken from the word alkali which means base. Referring to the name, alkalimetric titration is a method of measuring the base concentration of a solution using an acid standard solution. This type of titration is the type most frequently used.

In alkalimetric titration, the base is used as the titrant which is then dropped into the acidic titrate solution, so that the solution becomes neutral. When the moles of the base react with the same number of moles of acid in the titrate solution, the titration equivalence point will be reached. Next, the end point of the titration will be known using a certain titration indicator.

The final step of alkalimetric titration is the determination of the level or concentration of the sample. Of course this determination is made by applying the general formula of the titration, where the number of moles of the base must equal the number of moles of the acid. The number of moles of the base itself is known by multiplying the total volume required to reach the end point of the titration using the concentration of the base solution whose concentration is known.

Also read: Definition, How it Works, and Types of Acid-Base Titration

Types of Alkalimetric Titration

Furthermore, alkalimetric titrations can be further divided into two types:

1. Direct Alkalimetric Titration

The most commonly used type of alkalimetric titration is the direct alkalimetric titration. In this titration, the reaction between the base as the titrant and the acid as the titrate is carried out directly. By using the alkalimetric titration type, the concentration of the titrate solution can be known immediately after the titration process is complete.

One example of direct alkalimetric titration is the determination of the level of acetic acid (CH3COOH) or commonly called vinegar using a standard solution of potassium hydroxide as the titrant. In this titration process, simply drop the titrant whose concentration has been known slowly into the acetic acid solution whose concentration is still unknown.

After reaching the end point of the titration, the process will be stopped. Furthermore, the volume of KOH can be used directly to calculate the concentration of the titrate solution.

2. Indirect Alkalimetric Titration (Back Titration)

The difference between direct and indirect alkalimetric titration is that the determination of concentration is not carried out by directly dropping the titrant into the titrate solution. However, the concentration of the titrate solution is obtained indirectly from the result of the titration between the remaining reagent and the alkaline titrant.

This indirect alkalimetric titration is also commonly called back titration. Back titration is generally used because of the slow reaction between the titrant and the titrate solution, the instability of the titrate solution under study, or indicators that say that direct titration is not suitable. These factors make direct titration ineffective because in the direct titration process, the reaction must proceed as quickly as possible so that the end point of the titration can be seen immediately.

An example of applying a reverse alkalimetric titration is the determination of zinc oxide content. The zinc oxide titration process is usually carried out with sulfuric acid but cannot be done directly. This is due to zinc oxide which has a slow reaction kinetics in sulfuric acid and also has a slow dissolving process. Therefore, zinc oxide is first dissolved in sulfuric acid through heating in order to speed up the reaction and the dissolving process.

Carrying out the titration process certainly requires the right titration tool. In this case, Hyprowira is the most appropriate solution if you need a titration tool. Hyprowira provides a titration tool from Mettler Toledo in the form of a Potentiometric Compact Titrator which will make it easy to determine the sample weight for the Total Acid Number test. Immediately visit the Hyprowira page and get an alkalimetric titration tool according to your needs!

Also read: How to Use Karl Fischer Titration You Need to Understand