Tuesday, November 30, 2021

Pharmaceutical Applications of Column Chromatography

Column chromatography is a separation technique that is used to purify compounds based on their hydrophobicity or polarity. The principle of column chromatography depends on the differential adsorption of a solute by the stationary phase (adsorbent). The mixture of complex molecules of analytes are separated based on differential partitioning among a stationary phase and a mobile phase, there are various sizes of the column are available for this technique.

In the process, the analytes to be separated are placed on top of a solid adsorbent-packed column. Then the mobile phase is loaded into the column at the top and the column is allowed to flow slowly and continuously. Components with less adsorption and affinity toward the stationary phase travel rapidly than those with higher adsorption and affinity for the stationary phase. Fast-moving components are eluted first, followed by slow-moving components.

Different types of column chromatography such as adsorption column chromatography, partition column chromatography, gel column chromatography, and ion-exchange column chromatography are used to separate the active ingredients by various methods.

Applications of column chromatography:

  • Column chromatography can be used to isolate many classes of drugs and components such as glycosides, plant extracts, alkaloids, amino acids, formulations, and drugs. 
  • Used for separation of the mixtures of compounds. 
  • It is used to remove impurities or the purification process. 
  • In column chromatography Impurities in a compound can be separated by using the appropriate mobile phase and a stationary phase. 
  • It is applied to the separation of active constituents. 
  • From the crude extracts, formulation, active constituents, plant extract necessary constituents can be isolated by this type of chromatography.
  • Column chromatography is used for the estimation of the drug in the formulation. 
  • From the biological fluids, metabolites can be separated using column chromatography.
  • Using this method, it is possible to the estimation of the drug in the crude extract.
  • For the isolation of active ingredients from plants, column chromatography is the most preferred and only separation technique in phytochemistry.

Chromatography is commonly used in chemical and life science research for a variety of purposes. The importance of chromatography techniques can be seen in their widespread use in a variety of sectors for a variety of objectives. HPLC, GC, TLC, adsorption, partition, affinity, and paper chromatography are some of the types of chromatography that have several applications in different fields.

General applications of chromatography are pharmaceutical industries, food industry, fuel industry, environmental analysis, forensic science, biotechnology, biochemical processes, and biological application, molecular biology studies, etc.


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Monday, November 29, 2021

What is primary standard in chemistry?

A primary standard is a highly pure reagent with a large molecular weight that can be easily weighed and used to initiate a chemical reaction with another component. 

To standardize an analytical method we use standards that contain known amounts of analyte. Standardization is a technique in titration for establishing the exact concentration of a prepared solution by using the standard solution in the form of reference. The precision of standardization relies on the reagents and glassware used to prepare the standards. Standard solutions are made with standard components and have precisely determined concentrations.

Standards are a substance that contains a known concentration of a drug and can be used to determine unknown amounts or calibrate analytical instruments. Analytical standards can be divided into two types, primary standards, and secondary standards.


A primary standard is a highly pure reagent with a large molecular weight that can be easily weighed and used to initiate a chemical reaction with another component, while a secondary standard is a material whose active agent content was determined by comparing it to a primary standard.

What is primary standard in chemistry?

A primary standard in chemistry is an extremely pure reagent (99.9% accurate), easily weighed, and gives an indication of the number of moles in a compound. A reagent is a chemical that is used to initiate a chemical reaction between two or more substances. Reagents are frequently used to determine the presence or amount of specific chemicals in a sample solution.

Primary standards are substances that do not react with the components of the air in the open state and retain their structure for a long time. They are extremely pure and stable, with specific chemical and physical properties.

Primary standards are commonly used in experiments of titration and other analytical chemistry techniques to determine the unknown concentration of solute. Titration is a technique that involves adding a small amount of reagent to a solution until a chemical reaction happens (endpoint or equivalence point). The reaction confirms that the sample solution is at a certain concentration. There are four types of titrations: acid-base, redox, precipitation, and complexometric titration.

Examples of the primary standard:

  • Potassium dichromate (K2Cr2O7) and sodium carbonate (Na2CO3), and potassium hydrogen phthalate (KHP)
  • In an acetic acid solution, potassium hydrogen phthalate can be used to standardize perchloric acid and an aqueous base.
  • The primary standard for silver nitrate (AgNO3) reactions is sodium chloride (NaCl).
  • Potassium dichromate (K2Cr2O7) is a primary standard for redox titrations
  • Sodium carbonate (Na2CO3) is a primary standard for the titration of acids
  • Potassium hydrogen iodate KH (IO3)2 is a primary standard for the titration of bases

Why are primary standards used in chemistry?

  • A primary standard is a measurement used in the calibration of work standards. Because of its accuracy and stability when exposed to other compounds, a primary standard is chosen. Primary parameters can be measured as a metric, such as a length, mass, or time.
  • In analytical chemistry, it is commonly used. as, a reagent that is easy to weigh, a higher equivalent weight is selected, is pure and is not likely to change in weight when exposed to humid conditions, and has low reactivity with other chemicals.
  • The use of a primary standard ensures that the concentration of the unknown solution is accurate. Because of a process error, the degree of trust in the concentration is slightly lower. However, for some substances, this method of standardization is the most reliable technique to obtain a consistent concentration measurement.
  • Primary standards are generally used to make standard solutions that have an exactly known concentration. 

Properties of primary standards:

  • They are unaffected by atmospheric oxygen
  • They have known molecular weight and method 
  • They are the dominant reactants
  • They are usually chemicals with a large molecular weight
  • Over a long period, they have a constant concentration/uniform composition

The following are the characteristics of a good primary standard that provide more advantages:

  • It has a high degree of purity
  • Has a non-toxic
  • It has low reactivity and high stability
  • Is affordable and easily available
  • It has a high equivalent weight
  • It has a high solubility
  • In humid vs dry environments, it is unlikely to absorb moisture from the air to lessen mass fluctuations.
In practical, some compounds used as primary standards achieve all of these requirements, although great purity is essential. Furthermore, a compound that is an excellent primary standard for one analysis may not be the best choice for another.

What is a primary standard solution?

A solution composed of primary standard compounds is known as a primary standard solution. A primary standard is a high purity (99.9%) material that can be dissolved in a known volume of solvent to form a primary standard solution. Zinc powder can be used to standardize EDTA solutions, after being dissolved in sulfuric acid (H2SO4), or hydrochloric (HCl) is an example of a primary standard solution.


Frequently Asked Questions (FAQ):


What is a secondary standard?
A substance that has been standardized against a primary standard for use in a specific analysis is called a secondary standard. To calibrate analytical methods, secondary standards are often used. Sodium hydroxide (NaOH) is often employed as a secondary standard after its concentration has been confirmed using the primary standard.

Why is the use of a primary standard solution important?
Primary standards are necessary to determine unknown concentrations or to prepare working standards in titrations.

What is the difference between primary and secondary standard?
A primary standard is a reagent that can be easily weighed and is representative of the number of a substance contains, while a secondary standard is a substance that has been standardized against a primary standard for use in a particular analysis.


References:
  1. Primary Standard Substance - QS Study. https://qsstudy.com/chemistry/primary-standard-substance. 
  2. Wikipedia contributors. "Primary standard." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 26 Oct. 2021. 
  3. Helmenstine, Ph.D. Anne Marie. “Learn About Primary and Secondary Standards in Chemistry.”
  4. Skoog, Douglas A., Donald M. West and F. James Holler. "Fundamentals of Analytical Chemistry 8th ed." Harcourt Brace College Publishers.

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Saturday, November 27, 2021

Difference between primary and secondary standard solution

The major difference between a primary standard solution and the secondary standard solution is that primary solutions have higher purity and lower reactivity, whereas secondary solutions have a lower purity and higher reactivity.

Standardization of solutions is an analytical chemistry concept that is essential for the accuracy of titration. Standardization is a method of determining the exact concentration of the prepared solution by using the standard solution in the form of reference. Standard solutions have exactly defined concentrations, and we make them with standard substances.

It is required to all solutions should be standardized using a primary standard solution before they can be used in the titration process. This is because, even if you weigh the accurate quantity of the sample analyte needed to make a 0.1 molL-1 solution, the concentration may not be exactly it might be the presence of impurities or manual error.



However, because the primary standard solution's concentration is 99.9% accurate, hence, to determine the exact concentration of the prepared solution, you can titrate it against an appropriate primary reference solution. Primary standard solution and secondary standard solution are the two major types of standard solutions. Primary standards are used to standardize secondary standard solutions, while secondary standards are used for certain types of analytical experiments.

What is the primary standard solution?

The primary standard solution is a solution composed of primary standard substances. A primary standard is a high-purity substance (99.9%) that can be dissolved in a known volume of solvent to produce a primary standard solution. These substances are commonly used to determine the unknown concentration of a solution that is capable of reacting chemically with the primary standard.

Primary standards are highly pure and stable and have unique chemical and physical characteristics. Thus, we can prepare pure solutions with these chemicals. Primary standards are commonly employed in titrations and other analytical techniques to determine an unknown concentration of solutes.

Primary standard solution example:

Examples of primary standards for the titration of solutions, based on their high purity, are:
  • Standardization of sodium thiosulfate (Na2S2O3) solution with potassium bromate (KBrO3).
  • Sodium carbonate for the standardization of aqueous acids such as sulfuric acid (H2SO4), nitric acid (HNO3), and hydrochloric acid (HCl) solutions.
  • Zinc powder (Zn) is used to standardize EDTA solutions.
  • Sodium chloride (NaCl) is used as a primary standard for silver nitrate (AgNO3) reactions.
  • Sodium carbonate (Na2CO3), potassium dichromate (K2Cr2O7), and potassium hydrogen phthalate (KHP) are some examples of primary standards.

What is a secondary standard solution?

A secondary standard solution is a chemical term for a solution that is titrated with a primary standard solution to determine its concentration. The secondary standard solution is composed of secondary standard substances for the specific analytical experiment. We should use primary standards to determine the concentration of these solutions. These types of standard solutions can be used to calibrate analytical instruments.

However, compared to primary standards, the purity of secondary standard solution is low, and the reactivity is high. Therefore, these solutions are easily contaminated due to their strong reactivity. Anhydrous potassium permanganate and sodium hydroxide are two common hygroscopic examples. Sodium hydroxide (NaOH) is a common example of secondary standard.

Difference between primary and secondary standard solutions:

    Difference between primary and secondary standard solution
  • Primary standard solutions are made from primary standard substances, while secondary standard solutions are solutions prepared specifically for certain analysis.
  • Primary standard solutions are highly pure (about 99.9%), while secondary standard solutions are not.
  • Primary standards are less reactive or non-reactive, while secondary standards are more reactive compared to the primary standard.
  • Primary standard solutions are rarely contaminated due to their low reactivity, while secondary standard solutions are quickly contaminated due to their high reactivity.
  • Primary standards are non-hygroscopic, while secondary standards are slightly hygroscopic.
  • Primary standard solutions are applied to standardize secondary standards and other reagents, while secondary standard solutions are applied for particular analytical studies.
  • Primary standards are unaffected by atmospheric oxygen, while secondary standards are influenced by the atmosphere or /environment.
  • Primary standards have known formulas and molecular weights, while the concentration of secondary standards varies over time.


Frequently Asked Questions (FAQ):


What is a primary standard?
A primary standard is an extremely pure reagent, has a high molecular weight, indicates the number of moles in a substance, can be easily weighed, and is used to cause a chemical reaction with another compound. Reagents are often used to determine whether a solution contains a specific chemical i.e. sodium carbonate (Na2CO3), potassium hydrogen phthalate (KHP), and potassium dichromate (K2Cr2O7), etc.

What is a secondary standard?
A secondary standard is a substance whose active agent content has been determined using a primary standard as a comparison. A secondary standard is made in the lab for a specific analysis and is generally standardized against a primary standard. NaOH, HCL, H2SO4, KOH, and KMnO4, etc. are some of the examples of secondary standards.


References:
  1. A.I. Vogel, Text Book of Quantitative Inorganic Analysis
  2. Helmenstine, Ph.D. Anne Marie. “Learn About Primary and Secondary Standards in Chemistry.”
  3. Wikipedia contributors. "Standard solution." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 16 Sep. 2021.
  4. Madhusha, November 07, 2017 Difference Between Primary and Secondary Standard Solution: Definition, Properties, Examples, https://pediaa.com/difference-between-primary-and-secondary-standard-solution/

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Friday, November 26, 2021

What is replacement titration in chemistry?

Replacement titration is a type of complexometric titration which is used when direct or back titrations fail to produce sharp endpoints. Metal-EDTA complex is introduced to this analyte (containing metal). The presence of a metal in the analyte displaces another metal from the metal-EDTA complex.

Titrimetry, or titration, is a volumetric analysis used to determine the amount of analyte in a sample solution. It consists of a titrant that is filled into a burette, an analyte into the conical flask where the reaction takes place, and an indicator is added to produce a color change.

A known concentration of titrant is added until the reaction is completed. The titration's endpoint or equivalence point is the point at which the reaction is complete. Acid-base titrations, redox titrations, complexometric titrations, and precipitation titrations are four types of titrations that use various chemical processes and principles.

What is complexometric titration?

Complexometric titration also known as chelatometry is volumetric analysis in which the endpoint is indicated by a colored complex. In this type of titration, an indicator is used that can provide a different color change in the titration, indicating the endpoint of the titration.

Metal ion concentrations in the solution are determined using complexometric titrations. Complexometric titrations are classified as back, direct, replacement, and indirect titration methods, etc.

What is replacement titration?

The replacement method can be used to determine metal when direct or back titrations do not provide sharp endpoints or when there is no suitable indicator for analysis. The metal to be analyzed is added to the metal-EDTA complex. The analyte ion displaces EDTA from the metal, which is then titrated with standard EDTA.

This technique of titration involves displacing magnesium or zinc ions from an EDTA complex with an equivalent quantity of metal ions and then titrating the Mg or Zn ions with a standard solution of EDTA. Mordant black (Eriochrome Black T) is used as an indicator. This titration can also detect cadmium, lead, and mercury.

Example of replacement titration:

The metal to be analyzed is added to the metal-EDTA complex. The analyte ion displaces EDTA from the metal, which is then titrated with standard EDTA.

For example, when determining Mn, an excess of Mg EDTA chelate is added to the solution of Mn. Because Mn forms a more stable complex with EDTA, the Mn ions quantitatively displace Mg from the Mg-EDTA solution. The liberated Mg metal is then titrated directly with a standard EDTA solution using the Eriochrome Black T indicator.

replacement titration


Frequently Asked Questions (FAQ):

What are the indicators used in complexometric titration?
Eriochrome Black T, Fast Sulphon Black, Eriochrome Red B, and Murexide are common indications that are used in the complexometric titration.

What are the types of conductometry titration?
Acid-base titration, precipitation titration, replacement titration, redox (oxidation-reduction) titration, and complexometric titration are the types of conductometric titrations.

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Wednesday, November 24, 2021

What is back titration in chemistry?

Titration is the most popular quantitative and volumetric laboratory technique for determining the unknown concentration of an analyte by comparing it to the known concentration of a solution in the presence of an indicator. There are several types of titrations, such as acid-base titrations, redox titrations, precipitation titrations, and complexometric titrations, depending on the goals and process.


Complexometric titration, also known as chelatometry, is a type of volumetric analysis in which the endpoints are determined by colored substances. In these titrations, an indicator is employed to indicate the titration's endpoint, which is based on the development of a complex between the solute and the titrant. 

An example of complexometric titration is the determination of water hardness using EDTA and Eriochrome Black-T as indicators. Direct, back, replacement, and indirect complexometric titration are several types of complexometric titration.

What is back titration?

Back titration is a minimal two-step process in which the titrand is reacted with a specific, excess amount of titrant whose concentration is known. Rather than titrating the original sample, a known excess of the standard reagent is added to the solution, and the titration is performed. The standard titrant will then react with the solute, and the excess remains in the sample solution. The remaining amount of standard reagent can be determined using a back-titration.
“Back titration is a kind of titration that is performed in reverse and is also known as an indirect titration”

Back titration example:

Determination of acetylsalicylic acid in aspirin and determination of phosphate concentration by titration of excess silver nitrate with potassium thiocyanate are examples of back titration.

When is a back titration used?

  • Back titration is performed when the reaction between the analyte and the titrant is slow or the analyte is in an insoluble solid
  • When the molar concentration of an excess reactant is known but the strength or concentration of a molecule is unknown
  • When the acid or base is an insoluble salt
  • While determining the endpoint of a direct titration can be difficult, for example, titration of a weak acid and weak base
  • When a standard titration fails to find an endpoint, back titration is used

How is a back titration performed?

A back titration usually takes place in two steps: the volatile analyte reacts with an excess reagent first, and then a titration is performed on the remaining quantity of the known solution. It is a way of measuring the amount consumed by the analyte, by calculating the excess quantity.

What is direct titration and back titration?

A back titration involves adding an excess of standard titrant to the solute and titrating the excess titrant to determine how much is in excess, whereas a direct titration directly measures the concentration of the unknown compound, which involves adding a standard titrant to the analyte until the endpoint is reached.

What is back and blank titration?

Back titration is a titration that is carried out in reverse and is also known as an indirect titration, whereas a blank titration is a titration performed on a solution that is identical to a sample solution except that the analyte is not present, which is used to detect and correct systematic analysis errors.

What is the difference between titration and back titration?

In a titration, we normally add a chemically equal amount of standard solution to the analyte, while in a back titration we add an excess amount of standard solution to the analyte. Back-titrations are similar to normal titrations in that they follow the same general principles.

Advantages of back titration:

  • It does not need any special chemical or apparatus.
  • It can offer correct results.
  • It is advantageous when trying to figure out the amount of acid or base is in a non-soluble solid.
  • The process is easy to perform, similar to normal titration.
  • If the reverse titration endpoint is easier to identify than the normal titration endpoint, this method is useful.

 

 
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Tuesday, November 23, 2021

What is a blank titration and why is it necessary

A blank titration is one in which no analyte is present and only the solvent used in the sample solution is measured, which is employed to detect and correct systematic analysis errors.

A titration is a chemical method known as the volumetric or titrimetric method, it is a quantitative chemical analysis used for determining the precise amount of a solute in a sample solution.

The process involves drop-wise adding a known-concentration reagent (Titrant) to a solution containing an unknown-concentration reagent (Titrand) until the reaction between the two reagents is complete.


The equivalence point is the point where the amount of the reactants is equal. A color change at the endpoint, which approximates equivalence, is usually indicated with the help of a chemical indicator. When it comes to process, applications, and goals, there are various types of titrations, such as acid-base titrations, redox titrations, precipitation titrations, and complexometric titrations.

What is a blank titration in chemistry?

A blank titration is one in which no analyte is present and only the solvent used in the sample solution is measured, which is employed to detect and correct systematic analysis errors.
“Blank titration is a titration performed on a solution that is similar to the sample solution except for the absence of the sample”
In a blank titration, a fixed and known concentration of titrant is titrated into a solvent with zero solutes. The absence of solute or sample is the only difference from normal titration. This allows the amount of the reactive compound in the simple solvent to be known, and therefore the inaccuracy to be determined in future titration experiments with this solvent.

Example of blank titration:

To check for possible causes of error in the blank solution, a blank titration is performed without an analyte. For example, De-ionized water is slightly acidic, which might affect the results of acid-base titrations. Hence, need to run a blank titration to determine the concentration of H3O+ in the water and use it to adjust your analyte's concentration. This is useful in the case of very precise concentration is required.

blank titration

What is the reason for carrying out the blank determination?

Blank determination is a conclusive method that follows all steps of the analysis although it occurs without the use of a sample compound. It is used in the detection and correction of systematic analytical errors.

Why is it important to run a blank test?

Blank titration is performed to check that the solvent contains no compounds that may react with the titrant, or to estimate how much titrant would react with the pure solvent. This allows us to estimate the error that will occur during the actual titration experiment is conducted.

How to perform blank titration?

A blank titration is usually performed using the same process as a conventional titration. Titrant of known concentration which is filled in the burette is titrated with the solvent that has zero analytes which are poured in the conical flask. An indicator indicates the endpoint.

What is the endpoint of blank titration?

The endpoint of a blank titration is the same as a normal titration, in which the indicator causes the solution to change color.

How does a blank titration reduce titration error?

Blank titration can help to reduce titration error, as in the absence of solute the volume of titrant needed to reach the endpoint can be subtracted from the volume required in the presence of a solute.


Frequently asked questions (FAQ):


What is the difference between a direct titration and a back titration?
A direct titration involves adding a standard titrant to the analyte until the endpoint is reached, whereas a back titration involves adding an excess of standard titrant to the analyte and titrating the excess titrant to determine how much is in excess.

What materials do you need for titration?
Burette, pipette, conical flask, pipette stand, beaker, etc. are used to perform the titration.

What do you mean by blank and back titration?
Blank titration is a titration performed on a solution that is similar to the sample solution except for the absence of the sample, while a back titration is used when it is difficult to find an endpoint in a normal titration.
 
 
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Monday, November 22, 2021

What is self indicator with example?

The self indicator is essentially a chemical compound that can indicate the endpoint of titration or any other reaction, with self-participation in the reaction.

What is an indicator?

In chemistry, an indicator is a substance that can be added to indicate the equivalence point of the titration. Color indicators that change color when exposed to acidic or alkaline liquids are commonly used to detect pH. There are two approaches to explain the theory of acid-base indicators: Ostwald's theory and the quinonoid theory.

Natural indicators, artificial indicators, and olfactory indicators are the three categories of indicators used in chemistry. Indicators such as phenolphthalein and methyl orange are commonly used for titration in research, several types of applications, and in the laboratory of science classrooms for practical purposes. As well as a litmus paper (Blue or Red), pH paper, universal indicator, and pH meter are often used to detect the pH of a substance.


In the titration procedure, the sample or titrand to be analyzed is poured in a conical flask; two to four drops of a suitable indicator are added, followed by drop-by-drop addition of titrant of known strength or concentration to a burette until the chemical reaction is completed. The indicators can be a self indicator, internal indicator, and external indicator; however, the internal indicators are most commonly used for different types of titration.

What is a self indicator?

A self-indicator is a chemical compound that itself indicates the endpoint of titration or any other reaction involving self-participation. Since the self-indicator indicates the endpoint or equivalence point of reaction, hence there is no need of adding any additional indicator.

Potassium permanganate (KMnO4) is one of the major examples of self-indicator. It is used in oxidation-reduction (redox) titrations that disappear or re-appearing their pink color at the endpoint, as the reaction proceeds.
“A self-indicator is a chemical substance that indicates the titration's endpoint by itself”

Example of the self indicator:

KMNO4 is an example of a self-indicator. Potassium permanganate titrant act as a self-indicator in the presence of a reducing agent, changing color from pink to colorless. It is a versatile and powerful oxidant that may be used to determine the identity of a range of chemicals using direct or indirect titration. 

When it is used in redox titration, it is reduced to a brown-colored Mn2+ ion at the endpoint in acidic solutions, and the color change is observable. Since KMNO4 recognizes the endpoint, it does not require any other indicator during the titration.

How does KMnO4 acts as a self indicator?

Because of Mn's +7 oxidation state of Mn, KMnO4 solutions are dark purple. When employed as a titrant, the solution has a permanent pink color after the endpoint is reached and the KMnO4- is in excess (provided that the solution is initially colorless). As a result, KMnO4 serves as its own indicator.

Why do we use KMnO4 as a self indicator?

KMnO4 is a redox indicator. Mn has a wide range of valencies; Whenever Mn changes its valence state, its color changes. As a result, no external indication is required. It can serve as a self-indicator to indicate the endpoint of the reaction.


Frequently asked question (FAQ):


Which indicator is used in permanganometry?
The process does not need an external indicator, Potassium permanganate, which is used in permanganometric titrations, is termed an auto-indicator since its color changes based on the type of reaction.

Why H2SO4 is used in the titration of KMnO4?
Because it is neither an oxidizing nor a reducing agent, dilute H2SO4 (sulfuric acid) is ideal for redox titration.

What is the purpose of indicator in titration?
The objective of an indicator in titration is to detect the titration's endpoint. An indicator is a substance that changes color when exposed to acidic or basic solutions.
 
 
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Saturday, November 20, 2021

What is the purpose of titration?

The basic purpose of titration is to determine the unknown concentration of analyte in a sample using an analytical technique.
OR
Titration is used to determine the equivalence point, the point at which chemically equivalent amounts of reactants are mixed.


What is titration and why is it useful?

Titration, commonly known as the volumetric or titrimetry method, is quantitative chemical analysis. It is a frequently used analytical technique in chemical laboratories for estimating the concentration of a solute in a sample solution because of its various applications and advantages. In chemistry, titration is important because it allows precise measurement of the analyte concentrations in solution.

Titration is useful in pharmaceutical analysis, wastewater analysis, environmental analysis, food industry, beverage industry, and classes of chemistry since it allows for the accurate determination of compound’s concentration and can be performed in a variety of reactions, including acid-base, redox, complexometric, and precipitation reactions.


Titration involves three essential elements: Titrant, which is a liquid with known molarity or normality, titrand, which is the sample or liquid that needs to be measured, and a calibrated apparatus (burette) for dispensing the titrant into the titrand drop by drop. When the titration reached an endpoint or equivalence point, the volume of the titrant was used to calculate the unknown concentration. Usually, an indicator is used to determine the endpoint of the titration.

Purpose of titration:

The basic purpose of titration is to determine the unknown concentration of analyte in a sample using an analytical technique.
OR
The objective of the titration is to find the equivalence point; it is a point where chemically equivalent amounts of reactants are mixed. The amount of reactants mixed at the equivalence point depends on the stoichiometry of the reaction.

purpose of titrationThe most common purpose of titrations is generally used to determine an unknown concentration of a component (Solute) in a solution by reacting it with another compound's solution (Titrant). The concentration of the analyte can be calculated using the titrant's known concentration, the volume of titrant added, and the reaction's stoichiometry.


In addition, titrations can be used for a variety of purposes, including:
  • To determine the molarity of a solution with an unknown concentration
  • To find out the mass of an acid or a basic salt
  • To determine the degree of purity of a solid
  • To find out what percentage mass of a solute is in a sample solution

What is the main purpose of acid-base titrations?

An acid-base titration is a commonly used method of determining the unknown concentration of an acid or base by accurately neutralizing it with a known concentration of acid or base. This allows us to quantitatively analyze the concentration of the unknown solution.

E.g. Titration of hydrochloric acid (HCl) with sodium hydroxide (NaOH) by using phenolphthalein indicator. Strong acid-strong base, weak acid-strong base, strong acid-weak base, and weak acid-weak base are the 4 types of acid-base titration.

What is the purpose of redox titration?

Redox titration, also known as oxidation-reduction titration, can precisely measure the concentration of an unknown solute, by measuring against a standardized titrant. The objective of redox titration is to determine the concentration of an unknown sample solution (analyte) containing an oxidizing or reducing agent.

E.g. Titration of potassium permanganate (KMnO4) against oxalic acid. Permanganometry, iodometry/iodimetry, cerimetry, direct titration, and back titration are the types of redox titration.

What is the purpose of complexometric titration?

Complexometric titrations are mainly used to determine metal ions by using complex-forming reactions. It is a volumetric analysis because analyte, titrant, and even the volume of the indicator all play a part in the titration.

E.g. determination of water hardness using EDTA with Eriochrome black-T. Direct, back, indirect, and replacement are the types of complexometric titration.

What is the purpose of precipitation titration?

Precipitation titration is a type used to determine chloride using silver ions, in which the analyte and titrant react to form a precipitate throughout the titration process.

Precipitation titration is used to determine the halide ions, to analyze various drugs, to measure salt content in various food, beverages, and water, and also used in the pharmaceuticals industries. Volhard’s, Fajan’s, and Mohr's methods are the types of precipitation titration.

What is the purpose of blank titration?

Blank determination is a technique that follows all steps of the analysis but without the use of a sample. The purpose of blank titration is to make sure that either the solvent doesn't contain substances that could react with the titrant. This allows us to estimate the amount of error that will occur during the actual titration experiment is conducted.

What is the purpose of indicator in titration?

Compounds that change color when exposed to acidic or basic solutions are known as an indicator. The purpose of an indicator in a titration is to detect the endpoint of the titration by changing color where pH change occurs. E.g. Methyl orange turns red in an acidic medium, while it turns yellow in basic conditions.

What is the purpose of standardization in titration?

Before beginning the titration, we standardize the titrant each time. The purpose of standardization is to determine the exact concentration of a prepared solution. For a standardization process, a standard solution that is filled into the burette is required as a reference. There are two types of standard solutions: primary standard solutions and secondary standard solutions.

What is the purpose of two concurrent readings in titration?

The term concurrent reading refers to the same value each time a titration with the same solution is performed. The purpose of two or three concurrent readings in titration is to ensure the reproducibility of results.
 
 
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