Tuesday, May 31, 2022

Why is a weak acid best titrated with a strong base?

An acid-base titration is a type of titration used to determine the concentration of an acid or base by neutralizing the acid or base with a known concentration of acid or base. Strong acid-strong base, weak acid-strong base, strong acid-weak base, and weak acid-weak base are the types of acid base titration.

In the titration of a weak acid with a strong base, protons are transferred directly from the weak acid to the hydroxide ion, in which the titrant is a strong base and the analyte is a weak acid. During titration, a titration curve indicates the strength of the corresponding acid and base as well as the pH change.

The titration curve showing the pH change throughout the titration of a strong base with a weak acid shows that initially, the pH changes extremely slowly and gradually. As the titration approaches the equivalence point, this indicates the formation of a buffer system. At the equivalence point and beyond, the curve is typical for titration of, for example, sodium hydroxide (NaOH) and hydrochloric acid (HCl). When there is an excess of NaOH, the pH change is the same as in any NaOH-dominated system. Generally phenolphthalein indicator is used for the titration of weak acids and strong bases.
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What will be the pH at the equivalence point of strong base weak acid titration?

In a titration, the equivalence point occurs when the amount of titrant added is sufficient to neutralize the analyte solution. At this point, the number of moles of titrant (standard solution) equals the number of moles of the unknown concentration solution.

What will be the pH at the equivalence point of strong base weak acid titration?

In the titration of a weak acid with a strong base, protons are transferred directly from the weak acid to the hydroxide ion.

In a titration of a weak acid with a strong base, the endpoint point is shifted from neutralization to the pH of the strong reagent (base). The equivalence point is reached when the moles of acid added stoichiometrically balances the moles of base added. In a titration of a weak acid with a strong base, the pH of the solution at the equivalence point is greater than 7.

For example, the reaction of the weak acid, acetic acid (CH3COOH) with a strong base, sodium hydroxide (NaOH).

What will be the pH at the equivalence point during the titration of a 1000 ml of 0.2 M solution of CH3COONa with 0.2 M solution of HCl?

  • A: 3+log√2
  • B: 3−log2
  • C: 3−log√2
  • D: 3+log2
The correct answer is option C: 3−log√2
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Which titration falls under the category of acid-base?

An acid-base titration is a quantitative analysis technique used to determine the concentration of an acid/base by neutralizing it with a standard solution of acid/base of known concentration.

In this kind of titration, a drop of an indicator that changes color to indicate the endpoint is added to the beginning. The indicator changes color as the pH of the solution changes. To determine the equivalence point and minimize indicator error, have to use an appropriate indicator.

Which titration fall under the category of acid base titration?

The estimation of weak and strong acids in titration falls under the category of acid-base titration.

According to the nature of acid and base neutralization reactions, they are classified as:
  • Strong acid and strong base:
Example-HCL + NaOH → NaCl + H2O
  • Strong acid and weak base:
Example-HCl + NH4OH → NH4Cl + H2o
  • Weak acid and strong base:
Example- CH3COOH + NaOH → CH3COONa + H2O
  • Weak acid and weak base:
Example- CH3COOH + NH4OH → CH3COONH4 +H2O

In chemistry, the concentration or measurement of an analyte in a sample can be determined using titration. There are mainly four titration classifications based on the interaction of the sample with the added titrant. In an acid-base titration, the acid or base concentration can be determined. Therefore, the result will indicate how strong or weak the acid or base is.
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Monday, May 30, 2022

What type of a reaction is acid-base titration?

In chemistry, titration is an analytical technique that estimates the analyte concentration in a solution by adding a titrant of known concentration that reacts with the sample analyte in a stoichiometric manner, allowing the concentration of the analyte to be calculated. Acid-base, complexometric, redox, and precipitation titration are the types of titrations.

An acid-base titration is a method of quantitative analysis used to find out the concentration of an acid/base by neutralizing it with a known-concentration standard solution of base/acid. A pH indicator is used to monitor the progress of the acid and base reaction.

What type of reaction occurs during an acid-base titration?

Acid-base titrations use a neutralization reaction in which one species neutralizes another, resulting in water and an ionic salt. In a neutralization reaction, an acid and a base react in an aqueous solution to form salt and water.

An acid-base titration is all about the practical application of acid and base using an indicator (phenolphthalein, methyl orange, methyl red, etc.) to identify the endpoint, the volume of acid used, and average titre, etc. The acid-base reaction is represented by the formula equation of acid reacting with a base to produce salt and water (Neutralization reaction).


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Thursday, May 26, 2022

What causes the temporary and permanent hardness of water?

Hard water is a type of water that contains a high concentration of minerals. When water percolates through deposits of limestone, chalk, or gypsum, hard water is produced. It is composed of bicarbonates of calcium, magnesium, and sulfates. Permanent hardness and temporary hardness are the two types of water hardness. Generally, the hardness of water is determined by complexometric tritration, titrating with a standard solution of the complexing agent ethylene diaminetetraacetic acid (EDTA).

The salt responsible for the permanent hardness of water is the presence of chlorides or sulphates of calcium or magnesium or both. The salt responsible for the temporary hardness of water is the presence of bicarbonates of calcium and magnesium or both.

 
Permanent hardness of water is caused by Temporary hardness of water is caused by
The presence of chlorides or sulphates of calcium or magnesium or both The presence of bicarbonates of calcium and magnesium or both.

Which salts are responsible for the hardness of water?

The salts responsible for water hardness are calcium, magnesium, and iron (II) ions. Generally, water contains naturally dissolved salts such as magnesium (Mg), calcium (Ca), chlorine (Cl), sodium (Na), iron (Fe), etc., and 55 percent of these are Ca and Mg, which are responsible for the hardness of the water.

What is the cause of the temporary hardness of water?

The presence of dissolved bicarbonate salts such as calcium bicarbonate (Ca (HCO3)3) and magnesium bicarbonate (Mg (HCO3)2) causes temporary hardness. These salts are composed of calcium and magnesium cations and bicarbonate and carbonate anions. The presence of these metal cations makes water hard.

What is the cause of the permanent hardness of water?

Permanent water hardness is caused by the presence of calcium chloride (CaCl2), calcium sulfate, magnesium chloride (MgCl2), and magnesium sulfate (MgSO4) in water, which do not precipitate when the temperature rises.


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Wednesday, May 25, 2022

Why the endpoint of titration is wine red to blue in the hardness determination?

Complexometric titration or chelatometry is a method of volumetric analysis in which the colored complex is used to determine the endpoint of the reaction. Complexometric titrations using EDTA are based on the fact that many metallic ions form stable complexes with this tetradentate ligand.

The amount of hard water cations in water is measured as 'hardness.' Calcium, magnesium,  zinc, iron, and other polyvalent metal ions are among the hard water cations. The main contributors to the water hardness in most samples are Ca2+ and Mg2+ ions. Titration with the complexing agent EDTA is a simple way to quantify calcium and magnesium. Temporary hardness and permanent hardness are the two types of hardness.

Why does the steel blue color of the EBT indicator change into a wine red color when added to hard water?

At pH 10, EBT turns blue in a buffer solution which is an aqueous solution containing a weak acid and its conjugate base, or vice versa. When calcium ions are added, it turns red. The ions that cause water hardness, such as calcium, and magnesium turn the EBT indicator from steel blue to wine red.

Why a blue color appears at the endpoint in the hardness determination experiment by EDTA?

Eriochrome Black T has a loosely binding to metal ions, whereas EDTA has a significant binding to metal ions. When all metal ions are bound to Ethylenediaminetetraacetic acid, the indicator EBT in the sample remains free and the solution appears blue.

What happens when EBT is added to hard water?

When the eriochrome black T (EBT) indicator is applied in the sample of hard water with a pH of about 9 to 10, it produces a wine red colored unstable complex with Ca2+ and Mg2+ ions in the sample.

What is the reason for the blue color observed at the endpoint in the estimation of the hardness of water?

Additional EDTA removes the magnesium ions from the Eriochrome black-T indicator after all free calcium and magnesium have been bound by EDTA, restoring it to its uncomplexed blue color, and an endpoint is determined.

How is EDTA used to measure the hardness of water?

The presence of calcium ions and magnesium ions in water causes hardness. At a specific pH, EDTA interacts quantitatively with the ions. As a result, the ions and hence the hardness can be measured using eriochrome black-T and hence the hardness.

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Why is the buffer solution used in the determination of hardness of water?

Complexometric titration (also known as chelatometry) is a type of volumetric analysis that uses the formation of a colored complex to identify the titration's end point. Complexometric titration is used to determine the hardness. The hardness of water is estimated by titrating it with a standard solution of the complexing agent ethylene diamine tetra acetic acid (EDTA/EBT).

Water hardness is the total calcium and magnesium ion concentration in a water sample expressed as calcium carbonate concentration. Temporary hardness and permanent hardness are the two types of hardness.

Why we use buffer solution in temporary hardness of water:

When estimating the water hardness, an indicator dye is employed that turns the solution pink when Mg2+ and Ca2+ are present in the sample, or blue when all of the metal ions have interacted with the EDTA4-. As we know, the pH must be about 10.00 for the EDTA to release its H+ ions and yield the EDTA4- solution required for the reaction with Ca2+ and Mg2+.

The reaction (EDTA → EDTA4- + 4H+) changes the pH of the entire solution on its own, therefore we keep adding EDTA solution until the solution is blue and all traces of pink have disappeared. As a result, we'll need a buffer that will keep the overall pH of the solution at 10.00 even if we have to add a significant amount of EDTA.


Which buffer added during the determination of the hardness of water?

In EDTA titration, an ammonium hydroxide (NH4OH)-ammonium chloride (NH4Cl) buffer solution of pH 10.00 is used, because it resists the change in pH.
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Monday, May 23, 2022

How do you measure permanent hardness by EDTA titration?

Learn about the estimation of the permanent hardness of water by the EDTA complexometric method through a laboratory experiment or practical.

Aim:

To determine the amount of total hardness present in a given sample of water by the EDTA titration method.

Requirements for a water hardness test:

Glasswares: burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, wash bottle, etc.

Reagents: LR grade ethylenediaminetetraacetic acid (C10H16N2O8) solution, standard solution of calcium carbonate (CaCO3), erichrome black-T indicator (C20H12N3O7SNa), buffer solution, etc.

Apparatus: Digital/analytical balance.

Theory:

At pH = 9-10, EDTA forms stable, colorless complexes with Ca2+ and Mg2+ ions present in water. To maintain the pH of the solution between 9 and 10, a buffer solution of NH4Cl + NH4OH is used. As an indicator, Eriochrome Black-T (EBT) is used. The water sample has to be treated with buffer and EBT indicator, which form unstable, wine-red colored complexes with the Ca2+ and Mg2+ present in the water.

Procedure for standardization of EDTA:

  • Pour 20 ml of standard hard water into a conical flask using a pipette.
  • Then, add 5 ml of buffer solution and 2-4 drops of EBT indicator. The initially blue indicator would become wine-red.
  • Titrate it with EDTA solution until the wine-red color turns blue, which is the endpoint. Consider the burette reading to be V2 ml.
  • Repeat the titration three times to get accurate results, properly record the readings of the burette and calculate.

Procedure for the determination of total hardness:

  • Instead of standard hard water, repeat the above titration procedure using hard water samples. Consider the EDTA burette reading to be V3 ml.
  • The procedure for the determination of permanent hardness:
  • Measure the 100 ml sample of hard water and pour it into a beaker.
  • To remove temporary hardness, boil it to about half the volume and then cool it to ambient temperature.
  • Using filter paper, remove insoluble CaCO3 and MgCO3 by filtration.
  • Make up the 100 ml volume by adding distilled water.
  • Transfer 20 ml of this solution to a conical flask using a pipette.
  • Then, repeat the above titration process steps as mentioned. Consider the burette reading to be V4 ml.

Observation table:

Sr. No.

Content in conical flask

 

Burette reading

Volume of titrant used (ml)

Initial

Final

1

 

 

 

 

2

 

 

 

3

 

 

 

 

Mean:



Calculations:

Calculation for standardization of EDTA:

M1V1 = M2V2
Where,
M1 is the molarity of standard hard water.
V1 is the volume of standard hard water in a conical flask
M2 is the molarity of EDTA.
V2 is the volume of EDTA consumed.

Calculation for estimation of permanent hardness:

M2V2 = M4V4
Where,
M4 is the permanent hardness of sample water
V4 is the volume of the hard water sample in the conical flask.


Result:

The hardness of the given water sample has been determined to be:
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Redox titration: Principle, Types, Indicators, Applications, and Advantages

Learn about the principle, types, and applications of redox titration, which is a type of titration based on a redox reaction between analyte and titrant.  

Titration is a type of quantitative chemical analysis used to determine an analyte's unknown concentration. It is also known as titrimetry referring to volumetric analysis because volume measurement is important in titration. The titrant is added from a burette until the reaction is complete, and an indicator is usually employed to signify the equivalence point or endpoint.

 Titration consists of four types based on the different procedures and goals such as including acid-base, complexometric, precipitation, and redox titration.

What is redox titration explain with example?

A redox titration is called oxidation-reduction titration it is an oxidation-reduction process that takes place between an oxidizing and a reducing agent. In this type of titration, a chemical reaction occurs with the transfer of electrons to the reactant ions of aqueous solutions. 
Principle and types of redox titration

In the oxidation-reduction titration process, an oxidizing compound is titrated with the standard solution of the reducing agent, or a reducing compound is titrated with a standard solution of an oxidizing agent.

It is used for the analysis of organic solutes and generally evaluating chlorination. In an oxidation-reduction (redox) titration, generally, a potentiometer or redox indicator solution is used. 

Treating an iodine solution with a reducing agent to form iodide while using a starch indicator to aid determine the endpoint of the titration is the most common example of redox titration.
 

What is the principle of redox titration?

The principle involved in oxidation-reduction (Redox titration) is that the oxidation process involves the loss of electrons while the reduction process involves the gain of electrons.

Oxidant + ne ↔ Reductant

The following are the key characteristics of redox reactions which consist of both oxidation and reduction reactions.

Oxidation reaction:
The following are examples of how a solute can be oxidation reaction:
Oxygen atom addition
  • Hydrogen atom removal
  • Electron donation or loss
  • An overall enhance in the substance's oxidation state
Reduction reaction:
The following are examples of how a solute can be reduction reaction:
  • Hydrogen atom addition
  • Oxygen atom removal
  • Accepting electrons
  • Reduction in the oxidation state of the analyte

Redox titration curve:

It is important to understand the shape of the redox titration curve to evaluate it. The titration curve of a complexometric titration or an acid-base titration explains how the concentration of H3O+ or Mn+ varies as titrant is added. In redox titrations, it is more suitable to monitor the potential of the titration reaction rather than the concentration of a species.  

Indicators used in redox titration:

Potassium permanganate, iodine, ceric ammonium sulphate, phenanthroline blue, methylene blue, ferrous ions in dichromate solution, 1, 10 phenanthroline monohydrate, 2,2’-bipyridine, 5,6-dimethyl phenanthroline, and safrannin-T. Etc. are the commonly used redox indicators. 

The endpoint of redox titrations can be determined in a variety of ways such as self indicators, external Indicators, redox indicators, and instrumental techniques, etc. 

The redox indicators are indicators that exhibit a reversible change of color between oxidized and reduced forms and undergo a specified color change at a specific potential. These are indicators are weak reductants or oxidizers that have different colors in their reduced and oxidized forms. 

The color changes take place within a specific redox potential transition range, which must include the redox potential at the equivalence point in the redox titration to be performed.

If using an oxidizing volumetric solution, the indicator's redox potential should be greater than the potential of the solution, and when using a reducing volumetric solution, it should be lower.

Types of redox titration:

There are different types of redox titration based on the titrant used they are bromatometry, iodometry or iodimetry, cerimetry, permanganometry, and dichrometry, etc., and based on the method they are classified as direct titration, and back titration.

Iodometric titration:

The iodometric titration is a process for determining the concentration of an oxidizing agent in a sample solution. It is a type of redox titration that uses sodium thiosulphate, as a reducing agent to titrate iodine. A starch solution is used as an indicator in an iodometric titration because it can absorb the iodine (I2) that is released.

Iodimetric titration:

When an analyte that is a reducing agent is directly titrated with a standard iodine solution, the method is called iodimetry.

Bromatometry titration:

Bromatometry is the process that involves titration by oxidation using potassium bromate. It is a type of redox titration that is used to determine the bromination of a chemical indicator.

Cerimetric titration:

Cerimetry is a method of volumetric chemical analysis that can be used for analyses of nonstoichiometric levels that either oxidize Fe2+ or reduce Fe3+. It is a type of redox titration in which the endpoint is determined by a color change in the iron (II)–1, 10-phenanthroline complex (ferroin).

Permanganometric titration:

It is a type of redox titration in which the permanganate is used to determine the amount of analyte present in unknown samples solution. Permanganometry provides the detection and quantification of different chemical species, including manganese (II), iron (II), oxalate, nitrite, and hydrogen peroxide, etc.

Dichrometry titration:

It is a qualitative analysis in chemistry it involves the use of potassium dichromate (K2Cr2O7) which is used to determine the amount of solute in the sample.  

Applications of redox titration:

Redox titration is a quantitative chemical analysis method with a variety of applications, some of which are listed below.
  • Redox titration applied in the pharmaceutical field
  • It is used in public health and environmental analyses
  • It is used in the food industry
  • Applications of redox titration in different industries for research
  • Applications of redox titration in chemistry
  • Redox titration also used in the real-life applications
  • Redox reaction used in electrochemistry
  • The theory and practical taught in schools and colleges

Advantages of redox titration:

  • It's usually inexpensive and requires little equipment which is generally available in the lab
  • It does not need particular or expensive chemicals
  • Does not require high expertise, has a simple operating procedure
  • The analysis can be automated, with very precise results
  • Provides quick results

Disadvantages of redox titration:

  • It is a destructive technique that frequently consumes large amounts of the substance being analyzed
  • It requires reactions to take place in a liquid phase
  • It produces large volumes of chemical waste


Commonly asked questions on redox titration are as follows.

What are the factors affecting redox titrations?
The concentration of reactant, completeness of the reaction, temperature, and pH are the major factors that affect redox titration.

What are apparatus needed for titration?
Apparatus used to perform titration consist burette, stand, conical flask, pipette, funnel, beaker, volumetric flask, burette and wash bottle, etc., as well as some instruments such as pH meter, conductivity meter, colorimeter, Karl-Fischer titrator, and potentiometer, etc., are also used for different methods of titration.

What is the importance of the redox reaction?
A wide range of inorganic analytes can be analyzed using redox titration Oxidation-reduction reactions are extremely important not just in chemistry, biochemistry, and industrial processes, but also in geology and biology.
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Difference between titrant and titrand

The major difference between titrant and titrand is that the titrant is the reagent of known concentration which is filled in the burette, while titrand is the substance being titrated, generally which is in the conical flask.

Titrimetry, or titration, is a volumetric analysis that determines the concentration of analyte in a sample solution. It consists of a titrant that is filled into a burette, a pipette that is used to introduce the titrand into the conical flask where the reaction occurs. A titrant of known concentration is added until the reaction is complete i.e. chemical equivalence point.

The titration's endpoint is the point at which the reaction is complete. To find the endpoint, an indicator is used which changes the color of the solution at the endpoint or equivalence point. An instrumental method, such as a pH meter, potentiometer, or conductivity, can be used instead. Based on the chemical reaction between the titrant and the solute, there are four types of titrations, namely acid-base titration, redox titration, complexometric titration, and precipitation titration.


What is titrant?

In analytical chemistry, a titrant is a solution with a known concentration that is added to another solution to find out the concentration of a second chemical species. The titrant is also known as the reagent, titrator, or standard solution.

In simple words, a titrant is a known concentrated solution filled in a burette that is added to a solution whose concentration is to be determined.

What is titrand?

In analytical chemistry, a titrand is a solution whose concentration is determined by titration. It is feasible to determine the analyte concentration by reacting a known concentration and volume of a titrant with the analyte.

Example of titrant and titrand:

For example, the acid-base titration of sodium hydroxide and hydrochloric acid, in which NaOH is titrant and HCL is titrand.

Difference between titrant and titrand:

The major difference between titrant and titrand is that the titrant is the reagent of known concentration which is filled in the burette, while titrand is the substance being titrated, generally which is in the conical flask.

Difference between titrant and titrand

Is the titrant in the burette?

Yes, the titrant is always in the burette that is added to a solution whose concentration is to be determined.

What is titrant and titrand in titrimetric analysis?

In titrimetry, a reagent known as the titrant is added to a solution containing a reagent known as the titrand, and the two are allowed to react.

What is the difference between the titrant and the analyte?

The basic difference between the titrant and the analyte is that the analyte is any compound that undergoing analysis, whereas titrant is a reagent with a known concentration and volume that is used in titrations.
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Acid-base titration: Principle, Types, Applications and Procedure

Learn the principle of acid-base titration, classification of acid-base titration, indicators of acid-base titration, applications of acid-base titration, and procedure of acid-base titration.

Titration is a typical quantitative chemical analysis method used in laboratories to quantify the concentration of a particular analyte. Titration, also known as titrimetry or volumetric analysis, is a method in which the titrant is added from a burette until the reaction is complete, and an indicator is usually employed to mark the endpoint of the reaction. 

There are different types of titration such as acid-base, redox, precipitation, and complexometric titrations, however, in quantitative chemical analysis, redox titration and acid-base titration are most commonly used.


What is acid-base titration with example?

An acid-base titration is a quantitative analysis method used to determine the concentration of an acid or base by precisely neutralizing acid or base with a known concentration standard solution, in which a pH indicator to monitor the reaction.

The concentration of a solution (molarity) of an analyte solution can be determined if the acid dissociation constant (pKa) of the acid or the base dissociation constant (pKb) of the base is known. If the solute solution has a known solution concentration, the pKa can be calculated by generating a titration curve.

Principle of acid-base titration:


As described in the theory of acid-base titration, the principle involves using a burette and pipette along with a pH indicator to determine the concentration of an acid or basic.Usually, as in titration, a neutralization reaction occurs between acid and base, hydroxide ions and hydrogen proton, and water is formed. An indicator is a dye added to have to be change color, whose color depends on the pH of the solution.

It is dissolved in the sample solution and is often used to detect the endpoint of the titration which is also known as the equivalence point, where the color change occurs.
Acid base titration

Indicators used in acid-base titration:

The pH range of an indicator is the most essential property, which is reliant on the acid strength of the indicator. The pH range of an indicator is the range of pH values across which the indicator changes color from acid to base.

It ranges from the highest pH, where only the acid form can be seen, to the lowest pH, where only the base form can be seen. Since the indicator does not change color at certain pH levels, it is not sensitive to pH changes outside of its range.

Acid-base indicators are generally classified into below listed three groups.

1. The phthaleins and sulphophthaleins: example-phenolphthalein indicator
2. Azo indicators: example- methyl orange indicator
3. Triphenylmethane indicators: example- malachite green indicator

Selection of indicator in acid-base titration:

In acid-base titrations, different indicators are used. The selection of indicators depends on the type of titration and whose pH range falls within the pH change of the reaction.

  • Strong acid-strong base: The phenolphthalein is generally preferred due to color change seen more easily.
  • Weak acid-strong base: Phenolphthalein is more proffered for this titration because it changes sharply at the equivalence point.
  • Strong acid-weak base: Methyl orange is more proffered for this titration because it changes sharply at the equivalence point.
  • Weak acid-weak base: Because a vertical portion of the curve above two pH units is required, there is no indication is suitable for this titration.

Types of acid-base titration with their examples:

The acid-base titration is classified into four different types such as strong acid-strong base, weak acid-strong base, strong acid-weak base, and weak acid-weak base.

Strong acid-strong base:

As an experimental concern, it is one of the easiest titrations to perform among the four forms of acid-base titrations. It involves the complete dissociation of a strong acid and a strong base in water, resulting in a strong acid-strong base neutralization reaction. When the moles of acid and base are the same and the pH is 07.00, it reaches the equivalence point.

Weak acid-strong base:

In this type of titration, the protons are direct transfer from the weak acid to the hydroxide ion. In the reaction of a weak acid (acetic acid) with a strong base (NaOH), the acid and base react in a one-to-one ratio. At the equivalence point of a weak acid–strong base titration, the pH is larger than 07.00.

Strong acid-weak base:

In this type of titration, the acid and base will react to form an acidic solution. Throughout the titration, a conjugate acid is formed, which subsequently reacts with water to form hydronium ions. At the equivalence point of a strong acid-weak base titration, the pH is less than 07.00.

Weak acid-weak base:

Unlike strong acids and strong bases, the shape of a weak acid's or base's titration curve significantly depends on the acid's or base's identity and the associated acid ionization constant (Ka) or base ionization constant (Kb) (Kb). In the titration of a weak acid or a weak base, the pH also changes much more gradually around the equivalence point, which is greater or less than 07.00, respectively.

Examples:

  • Hydrochloric acid (HCl) and sulphuric acid (H2SO4) are two examples of strong acids.
  • Acetic acid (CH3COOH) and formic acid (CH2O2) are the two examples of weak acids.
  • Sodium hydroxide (NaOH) and potassium hydroxide (KOH) are two examples of strong bases.
  • Ammonia and methylamine are the two examples of weak bases.

Applications of acid-base titration:

  • Acid-base titrations are most commonly used to determine the unknown acid or base concentration of the analyte.
  • It is used as a quantitative chemical analysis.
  • It has the potential to be used in pharmaceutical applications.
  • It can be used in environmental analysis.
  • It is used to determine the barbiturates, aspirin, and amino acid.

Experimental procedure of acid-base titration:

  • Requirements: Conical flask, funnel, beaker, pipette, burette, burette stand, spatula, wash bottle, indicator, unknown solution, and standard solution.
  • Titration procedure:
  • Clean and dry all the glassware’s with distilled water and rinse the burette with the standard solution.
  • Fill the burette with a standardized solution, accurately measure the volume of the analyte, and add in the conical flask, also add a few drops of indicator using the pipette.
  • Titrate it with the standardized solution until the indicator changes the color. When the indicator permanently changes the color, the endpoint reaches.
  • Repeat the titration at least three more times and record the initial and final readings in the observation table and calculate the value.
Commonly asked quetions on acid-base titration are as follows.

What are the three theories of acids and bases? 
Arrhenius concept of acid and base, Bronsted-Lowry concept and Lewis concept are the three theories that identify a singular characteristic which defines an acid and a base.

Why phenolphthalein is used in acid-base titration?
In a strong acid-strong base titration a phenolphthalein indicator is chosen since it changes color in a pH range of 8.3 to 10.

Why is acid-base titration important?
The objective of a acid-base titration is to find out the concentration of an acid solution by titrating it with a known concentration of a basic solution, or vice versa until neutralization occurs.

Which indicator is used in acid-base titration?
Phenolphthalein, thymol blue, methyl orange, methyl yellow, methyl red, and phenol red, etc. are some of the examples of indicators used in acid-base titration.


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