Definitions and basic terms used in titration

Titration is also known as titrimetry or volumetric analysis. It is the method by which a solution is added to another solution under conditions where the added volume can be reliably determined. In quantitative analytical chemistry, it is used to measure the unknown concentration of an analyte.

Titrations are often associated with acid-base reactions, although they can also involve other types of reactions such as precipitation, redox, and complexometric titrations. An indicator is usually used to signal the completion of the reaction.

What is the definition of titration?

A titration is defined as “A technique/process for determining the concentration of an analyte using the least amount of known concentration reagent needed to produce a specific effect when reacted with a known volume of the test solution”.

Table of Contents: What is a definition of titration? What is a burette in chemistry definition? What is a conical flask in titration? What is titrant in titration? What is titrand in titration? What is analyte/titrate in titration? What is indicator in titration? What is standardization? What is standard solution in titration? What is primary standard in titration? What is secondary standard in titration? What is equivalence stoichiometric point? What is endpoint in titration? What is buffer in chemistry? What is pH in chemistry? What is pKa value in chemistry? What is titration curve in chemistry? What is normality in chemistry? What is molarity in chemistry? What is assay in chemistry?

What are the terms used in titration?

Burette:

A graduated glass tube having a tap at one end is used for titration to administer known volumes of liquid. It is used to accurately dispense small amounts of liquid with accuracy.

Conical or Erlenmeyer flask:

A conical flask is a particular type of laboratory flask that has a cylindrical neck, a conical body, and a flat bottom. In chemistry laboratories, conical flasks are often used to hold liquids and mix them by swirling.

Titrant:

A solution with a known concentration is filled in the burette that is added to another solution to find out the concentration of a second chemical species.

Titrand:

A titrand is a solution whose concentration is determined through titration. It is possible to calculate the analyte concentration by reacting the analyte with a titrant of known concentration and volume.

Analyte/Titrate:

A substance whose quantity or concentration is to be determined, preparing the analyte involves dissolving the substance being studied into a solution.

Indicator:

The indicator is a substance that changes color when introduced to acidic or alkaline solutions. The color indicators are used to determine the pH, and they can also be added to the reaction mixture to find out where the endpoint or equivalence point is for the different types of titration.

Phenolphthalein, methyl orange, erichrome black T, methylene blue, potassium permanganate, potassium chromate, dichlorofluorescein, ferric ion, etc. are a few examples of indicators.

Standardization:

Standardization is a process in titration used to determine the precise concentration (molarity or normality) of a prepared solution using a primary or a secondary standard solution. As a reference to the standardization process, a standard solution is essential.

Standard solution:

A standard solution is a solution whose concentration of a substance is accurately known. A known quantity of solute is dissolved to produce a particular volume. It is prepared with a standard substance (primary standard).

Primary standard:

A primary standard is an extremely pure compound used as reference material in titrations, quantitative analyses, and other analytical chemistry techniques. It is representative of the substance's molecular weight and is easily weighed.

Primary standards are commonly used to prepare standard solutions. It has a high level of purity, is non-hygroscopic, has a high equivalent weight, low reactivity, and is non-toxic.

Secondary standard:

A substance whose active agent content has been identified by comparison with the primary standard is called a secondary standard. It is often standardized against a primary standard.

Analytical instruments and procedures are calibrated using secondary standard solutions. Analytical equipment and analytical methods are calibrated using secondary standard solutions.

Equivalence point or stoichiometric point:

The equivalence point or stoichiometric point is the precise point in a titration at which the moles of one titrant equals the moles of the substance being measured. It is a point in a titration at which the reaction between the titrated substance and the titrant (standard) is completed.

Endpoint:

The endpoint is when the number of moles of the reacting titrant is more than the number of moles of the substance being tested. This is the point in the titration process where the indicator changes its color.

Buffer:

A solution consisting of an acid and its conjugate base is used to control the pH of a solution. It can neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable. In EDTA titration, a buffer solution is used as it is resistant to changes in pH that occur during the process.

pH:

pH stands for potential of hydrogen, a measure of the hydrogen ion concentration is equal to - log [H+]. The pH scale is usually from 0 to 14 in its range, The substances having a pH value of less than 7 that considered acidic, and basic or alkaline substances have a pH value of greater than 7, while 07 is considered a neutral pH.

pKa value:

The pKa value describes the acidity of a certain molecule. The strength of an acid is determined by how tightly a proton is retained by a Bronsted acid. When the pKa value is low, the stronger the acid and has a greater ability to donate its protons.

Titration curve:

A titration curve is the plot of the pH of the analyte solution against the amount of titrant added as the titration proceeds. The pH curves also help in determining the strength of the acid/base for determining the equivalence point. Additionally, it is possible to determine the concentration of the analyte.

Normality:

Normality can be defined as the number of grams or mole equivalents of a solute that are present in one liter of a solution. When we talk about an equivalent, we are referring to the number of moles of reactive in a compound. It is the number of grams of solute dissolved in one liter (1000 ml) of the solution, which is indicated by N.

Molarity:

The term "molarity" refers to the number of moles of solute dissolved in one liter (1000 ml) of solution. Molarity is indicated by M and it is also known as the molar concentration of a solution.

Assay:

A technique of analyzing a substance to ascertain its composition or quality is called an assay. An assay is a test that determines what compounds a substance contains. It is commonly used to determine the purity of a substance.

References:

1. “Titration.” Merriam-Webster.com Dictionary, Merriam-Webster, Available here 
2. Titrations:Terms’. SparkNotes, Available Here 
3. Wikipedia contributors. (2022, July 18). Titration. In Wikipedia, The Free Encyclopedia. Available Here 

You may also like this:

Importance of titration in chemistry
What is the process of titration?
Why is titration known as volumetric analysis?
Volumetric Analysis: Principle, Types, Procedure & Applications
Sources of error in titration
What solution usually goes in the burette in titration?
Preparation and standardization of oxalic acid using sodium hydroxide
Standardization of NaOH with oxalic acid
Standardization of NaOH with KHP
Standardization of HCl solution