Monday, September 6, 2021

Advantages and Disadvantages of pH meter

Depending on the application, the pH meter provides several advantages in various sectors, which is mentioned in this article.

The pH is the concentration of hydrogen ions in the sample or solution, for the determination of alkalinity or acidity of the solution in the range of pH 01 to 14 the pH meter is used. The solution is having more OH- remains alkaline whereas the solution having more H+ ion remains acidic.

The pH meter is used for determining the acidity level in pharmaceuticals, food and beverage, water, mining, petrochemicals, chemicals, and further industrial applications.

Advantages of pH meter:

  • This is a fast and simple process of measurement of pH.
  • This gives accurate results and gives a precise pH value.
  • It is used for various types of applications.
  • It covers the acidic as well as an alkaline range of pH (pH 01 to 14).
  • The user can calibrate it with the standard buffer solution (pH 07, pH 04, and pH 09.20).
  • An additional advantage of the pH meter is that it is portable.
  • As compared to reading a color strip or a pH indicator, a pH meter provide very accurate results.
  • A small battery-powered meter is a great choice while you are using it in a specific location.

Disadvantages of pH meter:

  • Deposits on the electrode membrane can interrupt the processes.
  • The pH meter is often needed to calibrate.
  • A special buffer solution is required to calibrate it.
  • The pH calibration may be influenced by temperature and carbon dioxide absorption.
  • There is a possibility of breaking due to fragile glass electrodes.

A pH meter is an apparatus that determines whether a sample solution is acidic or alkaline. pH meters are made up of a probe linked by a wire to a meter that displays the pH reading. In this technique of pH determination, the electrical potential of pH-sensitive electrodes is used as a measuring signal.


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Sunday, September 5, 2021

Advantages and disadvantages of normal phase chromatography

Chromatography is a technique for separating the mixtures of substances into their constituents based on their molecular structure and composition. High-performance liquid chromatography is essentially a more advanced version of column liquid chromatography. Instead of allowing a solvent to flow naturally through a column, it is forced through at high pressures by the pump. Based on the phase system (stationary) in the process, HPLC has different types such as normal phase, reverse phase, size-exclusion, and ion-exchange HPLC.

What is NP chromatography?

Normal phase chromatography is a type of HPLC chromatography. In which the mobile phase is moderately polar and the stationary phase is used to separate the analytes, which are freely soluble in moderate solvents. Less polar molecules in NP-chromatography elute first than the polar molecules. The retention time (RT) of the analyte is reduced by the use of more polar solvents in the mobile phase. Normal phase chromatography is preferable to separate molecules that differ in functional groups.

Advantages of normal phase chromatography:

  • The major advantage of normal phase chromatography is that it is used for the separation of polar molecules.
  • The non-polar solvent can be used to dissolve a sample.
  • It is perfect for isomer isolation, and very hydrophilic or hydrophobic molecules.
  • NP-chromatography is the most preferred technique for column chromatography.
  • Using low viscosity solvents can have higher flow rates.
  • It can be used for compounds that can decompose in water.
  • Nonpolar hydrocarbons such as hexane, diethyl ether, chloroform, octane, and mixtures are used as mobile phases in normal phase chromatography which is also more common such as methanol and acetonitrile. etc.
  • The nature of the added solvent is controlled by solvent selectivity.

Disadvantages of normal phase chromatography:

  • This method of separation is not suitable for the analysis of a wide range of compounds.
  • Due to the solvent de-mixing, gradient elution is not possible in this type of HPLC.
  • The formation of bubbles and evaporation can cause by lower boiling point solvents.
  • It is difficult to control the strength of the solvent.
  • The retention time of components can be variable.


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Difference between UV and PDA Detector in HPLC

PDA is essentially a UV/Vis detector with a variety of photodiodes, both of these detectors are simple to use and interpret. The major difference between the UV and PDA detector is that the PDA is superior to UV since it can scan the entire 190-800 nm range, whereas UV/Vis can only scan a single wavelength.

The different types of detectors such as UV/VIS, mass, fluorescence, refractive index, electrochemical, conductivity, light scattering, and IR detector are used in the HPLC analysis they are classified into two, namely solute and bulk property detectors. However each form of detector works on different working principle.

What is a UV detector in HPLC?

A UV detector is an in-line device that detects the UV absorbance of the HPLC eluent and generates a continuous signal that can be used to calculate the amount of chromophoric substances separating from the HPLC column. The compound can be recognized by measuring the absorbance of a sample solution of light at different wavelengths. UV absorption varies depending on which wavelength is used. UV detectors are classified as fixed wavelength, variable wavelength, or photodiode array detectors.

What is a photodiode array detector (PDA) in HPLC?

The photodiode array (PDA), also known as the diode array detector (DAD), is capable of measuring the whole range of wavelength in real-time, which may have additional benefits. It is a common UV detector that uses a photodiode imaging sensor to monitor the complete UV/VIS spectrum of material (Analyte/mobile phase) moving through the flow cell. 

Both absorbance and spectral data are produced by the detector, which can be used for quantification, identification, and peak purity analyses. Some manufacturers provide a DAD as a multiple wavelength detector without the spectral scanning function for a low-priced.

Overview of UV and PDA detector:

The UV, VIS, and PDA detectors are classified as absorbance detectors; they have a better sensitivity to the picogram (~ PG) levels and use them to detect compounds that have chromophore (light-absorbing compounds). UV is a widely used detector for ultraviolet spectroscopy as well as high-performance liquid chromatography.

The UV absorbance varies, depending on the mobile phase and the use of the wavelength. It is significant to select a suitable wavelength based on the type of analyte or component. A typical UV detector permits a selection of wavelengths between 190 nm and 400 nm. In contrast to a UV detector, a Visible (VIS) detector employs longer wavelengths, such as 400 nm to 800 nm. The detector that gives a broad wavelength selection, it's covering a range of UV-VIS (190-800 nm) called a UV/VIS detector.

Conversely, the PDA detector passes a wide range of light through the sample and after that, the light is isolated into individual wavelengths after going through the sample. The spectrum of light is directed to an array of photosensitive diodes. Every diode can quantify a diverse wavelength which considers the monitoring of numerous wavelengths at a time. Generally, just 1-2 wavelengths are used during the chromatographic run.

Difference between the UV and PDA detector in HPLC:

  • The key difference between the UV and PDA detector in HPLC is that the photodiode array detector can measure the peak area and height of the specific peak of the sample or analyte on the different wavelengths in the range of 200 to 800 nm, while a UV detector can determine the peak area and height in just one or two separate wavelengths, but the wavelength must also be selected before injecting the sample solution in the HPLC injector.
  • The UV/Vis detector can only detect a single wavelength at a time, whereas the DAD can scan a different wavelength (190-800 nm).
  • In a traditional HPLC system with a UV/VIS detector, the wavelength of the compound needs to be manually added, however in an HPLC system with a PDA detector, does not need to manually add the wavelength because it auto-detects the entire range.
  • High-performance liquid chromatography has capable of separating the degradant peaks from the drug substance. Due to the broad applications and advantages in pharmaceutical analysis, a photodiode array detector is more preferred over an ultraviolet detector to perform the forced deterioration, stress testing, and stability-indicating analytical methods.
  • PDA is a better option if you wish to scan a wavelength range, whereas if you know the absorption wavelength, you can use a UV/VIS detector to detect that particular wavelength.
  • The UV/Vis detector is time-consuming; whereas PDA provides rapid analysis hence it is a preferable choice for method development of sample analyte.

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Saturday, September 4, 2021

Prepare and standardize 1M sulphuric acid

Learn about the preparation and standardization of sulphuric acid (1M) using sodium carbonate as the primary standard and methyl orange as an indicator.

Aim:

To prepare and standardize 1M sulphuric acid using primary sodium carbonate.

Principle:

The principle of sulphuric acid standardization is an example of alkalimetry. When a strong acid is titrated with a strong base, the salt formed in the reaction is not hydrolyzed, so the pH of the final solution is not 07.00 at the endpoint of the reaction. Standardize H2SO4 solution (a strong acid) by titration with Na2CO3 solution (a strong base) by using methyl orange as an indicator. When sodium carbonate is titrated with sulphuric acid, the following reaction occurs.
Prepare and standardize 1M sulphuric acid

The molecular weight of sulphuric acid (H2SO4) is 98.07 g/mol.

How to prepare 1M sulphuric acid solution:

Take 54.00 ml of sulphuric acid (H2SO4) and dissolve in 500 ml of distilled water in a volumetric flask, and properly mixing it. Allow to cool at ambient temperature, make up the volume to 1000 ml.

How to prepare sodium carbonate solution (1M):

Take 286.15 gm of Na2CO3and dissolve in 500 ml of distilled water in a volumetric flask, and properly mixing it. Once it has completely dissolved, make up the volume to 1000 ml.

Procedure for standardization of 1M H2SO4:

In a clean conical flask, pipette out exactly 10.00 ml of 1M Na2CO3 solution and 2 to 3 drops of methyl orange indicator. Titrate the solution contents in the flask with sulphuric acid until the endpoint. The actual endpoint of the titration is indicated by a red color. To get accurate results, repeat the titration three times. Note down the burette reading in the observation table.

Observation table:

Sr. No.

Content in conical flask

Burette reading

Volume of titrant used (ml)

Initial

Final

1

 

 

 

 

2

 

 

 

3

 

 

 

 

Mean:

Calculations:

M1V1=M2V2
Where,
V1 = Volume of 1M Na2CO3 solution = 10 ml
M1 = Molarity of Na2CO3 solution = 1M
V2 = Volume of H2SO4 solution rundown
M2 = Molarity of H2SO4 =?
Therefore,
M2 = M1V1 / V2

Result:

The strength of the prepared sulphuric acid was found to be_____M.


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Prepare and standardize 0.1 M sodium thiosulphate

Learn about the preparation and standardization of 0.1 M sodium thiosulphate through a laboratory experiment or practical.

Aim:

To prepare and standardize 0.1 M sodium thiosulphate solution using potassium iodate as primary standard.

Reference: Indian Pharmacopoeia (IP) 2014; Volume-1, Page No. 316

Principle:

The principle of sodium thiosulphate standardization is based on redox titration utilizing the iodometric method in which potassium bromate is used as the oxidizing agent.

The 250 ml primary standard solution is prepared by a precisely weighed amount of the potassium bromate is dissolved in its water. To this 50 ml is carefully measured and 20.00 gm of potassium iodide (KI) and 30.00 ml of 2M hydrochloric acid (HCl) are added. Titrate the liberated iodine with sodium thiosulphate solution, until the blue color disappears, using starch solution as an indicator.
Prepare and standardize sodium thiosulphate

The molecular weight of sodium thiosulphate (Na2S2O3) is 248 g/mol.

How to prepare sodium thiosulphate solution (0.1M):

Take 25.00 gm of sodium thiosulphate and 0.20 gm sodium carbonate and dissolve in 500 ml of distilled water in a volumetric flask, and properly mixing it. Once it has completely dissolved, make up the volume to 1000 ml.

Procedure for standardization of 0.1M sodium thiosulphate solution:

  • Weighed correctly 0.2 gm of potassium bromate (KBrO3) and dissolve in 100 ml of distilled water in a volumetric flask, once it has completely dissolved, make up the volume to 250 ml with distilled water.
  • Take 50 ml of this solution and pour it into a conical flask.
  • Add 02.00 gm of potassium iodide (KI) and 3 ml of 2M HCl and titrate with sodium thiosulphate solution using starch solution as an indicator until the blue color disappears.
  • Equivalent factor: 0.02784 gm of KBrO3 per ml of 0.1M Na2S2O3.

Observation table:

Sr. No.

Content in conical flask

Burette reading

Volume of titrant used (ml)

Initial

Final

1

 

 

 

 

2

 

 

 

3

 

 

 

 

Mean:

Calculation:

Molarity of sodium thiosulphate = Weight taken of KBrO3 x molarity required / titration volume x equivalent factor.
Note:
Calculate how much potassium bromate is contained in the volume pipetted out based on the actual weight of the sample taken.

Commonly asked questions on titration are as follows.

Which primary standard is used for the standardization of sodium thiosulphate?
Potassium bromate is used as a primary standard is used for the standardization of sodium thiosulphate.

How will you prepare 0.1 M sodium periodate?
Take 21.4 g of sodium periodate (NaIO4) and dissolve in 1000 ml of distilled water in a volumetric flask, and properly mixing it

Why do we perform standardization of sodium thiosulphate solution?
We do standardization to determine the exact molarity or normalcy of the prepared sodium thiosulphate solution, which is important for calculations in titration or assay.
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Thursday, September 2, 2021

Conductometric titration of strong acid and weak acid against a strong base

Learn about the conductometric titration of strong acid and weak acid against a strong base through a laboratory experiment or practical.

Aim:

To determine the strength of a mixture of strong acid and weak acid using a strong base by conductometry.

Requirements:

Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, and wash bottle, etc.
Chemicals: LR grade acetic acid, sodium hydroxide (NaOH), hydrochloric acid (HCl), potassium hydrogen phthalate (KHP), and phenolphthalein indicator, etc.
Apparatus: Digital/analytical balance, and ultrasonicator, conductometer, and magnetic stirrer.

Principle:

A mixture of acids directly titrates with NaOH to determine its strength, in which hydrochloric acid is a strong acid, acetic acid is a weak acid, and sodium hydroxide is a strong base.

The conductometric titration principle is based on the fact that throughout the titration, one of the ions is replaced by the other, and these two ions usually have different ionic conductivities, causing the conductivity of the solution to change.

Conductometric titration of strong acid and weak acid against a strong base

Preparation of reagents and solutions:

Preparation of 1 M hydrochloric acid solution:

Click here to get the procedure of preparation of 1 M hydrochloric acid solution.

Preparation and standardization of 1 M NaOH solution:

Click here to get the procedure of preparation and standardization of 1 M sodium hydroxide solution.

Titration procedure:

  • All glassware should be cleaned and dried according to standard laboratory procedures.
  • Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
  • Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
  • Remove air bubbles from the burette and adjust the reading to zero.
  • Switch ON the instrument and calibrate the conductivity meter with a standard solution.
  • (Because potassium chloride (KCl) is soluble and stable, it is the most commonly used calibration solution for conductivity meters)
  • Once it is calibrated, rinse the platinum electrode with distilled water.
  • Take 75.00 ml of HCl, 25.00 ml of acetic acid, and pour it into a beaker.
  • Properly place the beaker on a stirrer and immerse both the platinum electrodes and set the burette properly on the beaker.
  • Note down the initial reading (conductance) of the sample i.e. millisiemens (mS) or micro-siemens (µS).
  • Turn on the stirrer and add 01.00 ml standardized NaOH solution from the burette at a time, properly record the readings.
  • Continue the titration process until the endpoint is reached.
  • The actual endpoint of the titration is indicated by a sharp increase in the conductivity of the sample.
  • Even after you've reached the endpoint, take a few more readings.
  • Plot the graph between conductivity (mho) vs volume of NaOH and calculate the strength of the sample mixture.

Calculations:

M1V1= M2V2
M2 = V1 M1 / V2

Where,
M1 is the molarity of sodium hydroxide
V1 is the volume of sodium hydroxide
M2 is the molarity of hydrochloric acid
V2 is the volume of hydrochloric acid

Result:

The strength of HCL was found to be___M.
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Tuesday, August 31, 2021

Conductometric titration of strong acid against strong base

Learn about the conductometric titration of strong acid vs strong base through a laboratory experiment or practical.

Aim:

To determine the strength of strong acid using a strong base by conductometry.

Requirements:

Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, and wash bottle, etc.
Chemicals: LR grade sodium hydroxide (NaOH), hydrochloric acid (HCl), potassium hydrogen phthalate (KHP), anhydrous sodium carbonate (Na2CO3), phenolphthalein indicator, and methyl red or methyl indicator, etc.
Apparatus: Digital/analytical balance, and ultrasonicator, conductometer, and magnetic stirrer.

Principle:

The principle of conductometric titration is based on the fact that one of the ions is replaced by the other during the titration, and these two ions usually differ in ionic conductivity, causing the conductivity of the solution to change during the titration.

HCl directly titrates with NaOH to determine its strength, in which sodium hydroxide is a strong base while hydrochloric acid is a strong acid.

Preparation of reagents and solutions:

Preparation of 1 M hydrochloric acid solution:

Take 85.00 ml of hydrochloric acid (HCl) using a pipette, dilute in 1000 ml of distilled water in a volumetric flask, and properly mixing it.

Preparation and standardization of sodium hydroxide:

Click here to get the procedure of preparation and standardization of sodium hydroxide (1M) solution.

Titration procedure:

  • All glassware should be cleaned and dried according to standard laboratory procedures.
  • Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
  • Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
  • Remove air bubbles from the burette and adjust the reading to zero.
  • Switch ON the instrument and calibrate the conductivity meter with a standard solution. (Because potassium chloride (KCl) is soluble and stable, it is the most commonly used calibration solution for conductivity meters)
  • Once it is calibrated, rinse the platinum electrode with distilled water.
  • Take 50.00 ml of hydrochloric acid, pour it into a beaker.
  • Properly place the beaker on a stirrer and immerse both the platinum electrodes and set the burette properly on the beaker.
  • Note down the initial reading (conductance) of the sample i.e. millisiemens (mS) or micro-siemens (µS).
  • Turn on the stirrer and add 01.00 ml standardized NaOH solution from the burette at a time, properly record the readings.
  • Continue the titration process until the endpoint is reached.
  • The actual endpoint of the titration is indicated by a sharp increase in the conductivity of the sample.
  • Even after you've reached the endpoint, take a few more readings.
  • Plot the graph between conductivity (mho) vs volume of NaOH and calculate the strength of hydrochloric acid (HCl).

Calculations:

M1V1= M2V2
M2 = V1 M1 / V2

Where,
M1 is the molarity of sodium hydroxide
V1 is the volume of sodium hydroxide
M2 is the molarity of hydrochloric acid
V2 is the volume of hydrochloric acid

Result:

The strength of hydrochloric acid was found to be___M.


Commonly asked quetions on conductimetric titrations are as follows.

What happens when a strong acid is titrated with a strong base?
In the titration of a strong acid-strong base, the acid and base will react to form a neutral solution. The hydronium (H+) and hydroxide (OH-) ions will react to form water at the reaction's equivalence point, resulting in a pH of 07.00.

What is the best indicator for strong acid-strong base titration?
Phenolphthalein indicator is the best indicator for strong acid-strong base titration.

Which is the example conductometric titration of a weak base with a strong acid?
The titration of hydrochloric acid (HCL) in the form of strong acid and ammonium hydroxide (NH4OH) as the weak base is an example of conductometric titration of a strong acid with a weak base.
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Monday, August 30, 2021

Potentiometric titration of strong acid against strong base

Learn about the potentiometric titration of strong acid vs strong base through a laboratory experiment or practical.

Aim:

To determine the strength of strong acid using a strong base by potentiometry.

Requirements:

Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, and wash bottle, etc.
Chemicals: LR grade sodium hydroxide (NaOH), sulphuric acid (H2SO4), potassium hydrogen phthalate (KHP), anhydrous sodium carbonate (Na2CO3), and phenolphthalein indicator, etc.
Apparatus: Digital/analytical balance, and ultrasonicator, potentiometer, and magnetic stirrer.

Principle:

In principle, determining the pH of a solution is easy since it is based on measuring the potential of a hydrogen electrode immersed in the sample solution.

Potentiometry is a type of electrochemical measurement. A strong acid is H2So4, while a strong base is NaOH. H2So4is directly titrated with sodium hydroxide to determine its strength. There is no indicator is required since the endpoint of the reaction can be detected by a sharp change in potential across the electrodes.
potentiometric titration of strong acid vs strong base

Preparation of reagents and solutions:

Click here to get the procedure of preparation and standardization of 01 M sodium hydroxide.
Click here to get the procedure of preparation and standardization of 01 M sulphuric acid solution.

Titration procedure:

  • All glassware should be cleaned and dried according to standard laboratory procedures.
  • Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
  • Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
  • Remove air bubbles from the burette and adjust the reading to zero.
  • Switch ON the potentiometer and calibrate the electrodes with pH 04.00, 07.00, and 09.20 standard buffer solutions.
  • Once it is calibrated, rinse the electrode with distilled water.
  • Take 50.00 ml of sulphuric acid, pour it to a beaker
  • Properly place the beaker on a stirrer and immerse both the electrodes and set the burette properly on the beaker.
  • Note down the initial reading of the sample i.e. e.m.f. in millivolts (mV).
  • Turn on the stirrer and add 01.00 ml standardized NaOH solution from the burette at a time, properly record the readings in mV.
  • Continue the titration process until the endpoint is reached.
  • The actual endpoint of the titration is indicated by a sharp increase in e.m.f.
  • Even after you've reached the endpoint, take a few more readings.
  • Plot the graph and calculate the strength of sulphuric acid.

Calculations:

M1V1= M2V2
M2 = V1 M1 / V2

Where,
M1 is the molarity of sodium hydroxide
V1 is the volume of sodium hydroxide
M2 is the molarity of sulphuric acid
V2 is the volume of sulphuric acid

Result:

The strength of sulphuric acid was found to be___ by plotting the normal 1st and 2nd derivative curves.


Commonly asked question on acid-base titration are as follows.

What is potentiometric acid-base titration?
The potentiometric titration technique is similar to the direct titration of a redox reaction. It's a useful method for characterizing an acid. Instead of using an indicator, the potential across the analyte, which is usually an electrolyte solution, is measured.

Which indicator can be used in the titration of strong acid and strong base?
Phenolphthalein indicator is most commonly used in the titration of strong acid and strong base which is one of the most suitable indicators for acid-base titration.

Which is the example titration of a strong acid with a strong base?
The titration of hydrochloric acid (HCL) in the form of strong acid and sodium hydroxide (NaOH) as the strong base is an example of titration of a strong acid with a strong base.


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Assay of sodium chloride

Learn about the assay of sodium chloride through a laboratory experiment or practical.

Aim:

To determine the percentage purity of given sample of sodium chloride using standard 0.1 N AgNO3 (Volhard’s method).

Requirements:

Glasswares: Burette, burette stand, conical flask, volumetric pipette, beaker, volumetric flask, funnel, glass rod, and wash bottle, etc.
Chemicals: LR grade silver nitrate (AgNO3), sodium chloride (NaCl), and potassium chromate (K2CrO4), etc.
Apparatus: Digital/analytical balance, and Ultrasonicator.

This practical is divided into two parts.
A. Preparation and standardization of silver nitrate (0.1 M)
B. To perform the assay of sodium chloride

Principle of assay of sodium chloride:

We already mentioned the principle of assay of sodium chloride in previous article (click here to visit).

Preparation and standardization of silver nitrate (0.1 M):

Click here to get the procedure of preparation and standardization of 0.1 M silver nitrate solution.

Preparation of sodium chloride solution (Sample):

Take 01 gm of sodium chloride and dissolve in 50 ml of distilled water in a volumetric flask, and properly mixing it. Once it has completely dissolved, make up the volume to 100 ml.

Titration procedure:

  • All glassware should be cleaned and dried according to standard laboratory procedures.
  • Before filling the burette for the titration, rinse it with distilled water and then pre-rinse it with a portion of the titrant solution. Pre-rinsing is required to make sure that all solution in the burette is the desired solution, not a contaminated or diluted solution.
  • Take the unknown stock solution of titrant in a clean and dry beaker then fill the burette using the funnel.
  • Remove air bubbles from the burette and adjust the reading to zero.
  • Take 10.00 ml of prepared sample solution of sodium chloride and pour it into a conical flask.
  • Add 2-3 drops of potassium chromate solution as an indicator.
  • Titrate the sample solution with silver nitrate solution until the endpoint is reached.
  • The actual endpoint of the titration is indicated by a brick red color at the end of the reaction.
  • To get accurate results, repeat the titration three times.
  • Properly record the readings of the burette.
  • Take their mean and calculate the molarity of the silver nitrate solution.

Observation table:

Sr. No.

Content in conical flask

Burette reading

Volume of titrant used (ml)

Initial

Final

1

 

 

 

 

2

 

 

 

3

 

 

 

 

Mean:

Calculations:

V x E x AM x 100 / W x RM

Where,
V is a volume of silver nitrate used
E is an equivalent factor
AM is an actual molarity
RM is a required molarity
W is the weight of the sample
For 1 ml of 0.1 M silver nitrate, the equivalent factor of PHP is 0.005845

Result:

The percentage purity of the sodium chloride (NaCl) sample was found to be_____.


Commonly asked questions on titration are as follows.

Which method is used for assay analysis of sodium chloride?
Assay analysis of sodium chloride is performed using the argentometric titration which is a type of titration involving the silver (I) ion, generally used to determine the amount of chloride present in the sample solution.

Which indicator is used in the assay of sodium chloride?
Assay of silver nitrate is based on the precipitation titration in which potassium chromate solution is used as an indicator that produces a brick red color at the end of the reaction.

Which titrant is used for the assay of sodium chloride?
The titrant in the sodium chloride assay is silver nitrate, which determines the chloride ion concentration. The precipitate of silver chloride is produced in the solution when silver nitrate is slowly.
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