Preparation of NaCl solution

Learn how to make different concentrations of molar and normal sodium chloride solutions, which are needed for many applications such as research, practical, pharmaceutical, chemical laboratory, and industries, etc.

Sodium chloride, also known as salt, is an ionic substance having the chemical formula NaCl with a sodium and chloride ions ratio of 1:1. It is a crystalline solid with an fcc structure, and it contains four ions of each Na+ and Cl-.

The reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) produces NaCl. In this reaction, both the acid and the base are strong. It can be found in the oceans and seawater, as well as in rock salt.

It is used in medicine (saline solution), fire extinguishers, the textile industry, and the paper industry as well as to produce sodium carbonate, and also used in water softening, etc.

Generally, a solid form of sodium chloride (NaCl) in different-sized packs is supplied in the market by vendors in the form of white/colorless crystalline or cubic crystals that are usually about 98-100% pure.

Table of Contents: Preparation of 0.02M NaCl Preparation of 0.05M NaCl Preparation of 0.1M NaCl Preparation of 0.2M NaCl Preparation of 0.25 M NaCl Preparation of 0.5M NaCl Preparation of 1M NaCl Preparation of 2M NaCl Preparation of 1% NaCl Preparation of 5% NaCl Preparation of 10% NaCl Preparation of 100 ppm NaCl Preparation of 1 ppm NaCl Preparation of 10 ppm NaCl

Requirements of glassware, chemicals, and apparatus:

Digital balance, beaker, pipette, pipette bulb, volumetric flask, measuring cylinder, glass rod, funnel, distilled water, AR/LR grade sodium chloride (NaCl), etc.

Calculation method:

In this case, we must determine the mass of sodium chloride (NaCl) required to make 1 molar solution of NaCl as well as the volume of the solution. We must use the molarity formula, which is,

Molarity= Moles of solute/Volume of solution

Step-by-step complete answer:

We must first determine the moles of NaCl. The solution is 1 L in volume and has a molarity of 1 M.

So, moles of NaCl can be calculated as,

Moles of NaCl=Molarity × Volume of solution= 1L

Moles of NaCl= 1 M ×1L=1 mol

Therefore, the mole of NaCl in the solution is 1 mol.

The mass of NaCl now is calculated using the number of moles of NaCl.

Number of moles= Mass/Molar mass

The mole of NaCl is 1 mol, and its molar mass is 58.44 g/mol.

1=Mass/58.44g/mol

Mass of NaCl=58.44 g

Therefore, to make a 1 M solution of NaCl, we need to dissolve 58.44 g of sodium chloride in 1 liter of distilled water.

Note:

Because the valency of NaCl is 1, the molarity and normality of the solution are the same.

How to prepare 0.02M NaCl solution?

Weigh accurately 01.17 g of sodium chloride and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare a 0.05M NaCl solution?

Weigh accurately 02.92 gm of sodium chloride and dissolve it in 250 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How do you make a 0.1M sodium chloride solution?

Weigh accurately 05.84 gm of sodium chloride and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare 0.2N NaCl solution?

Weigh accurately 11.69 gm of sodium chloride and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare 0.25M sodium chloride solution?

Weigh accurately 14.61 gm of NaCl and dissolve in 700 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 01 liter with distilled water, and properly mix it.

How to prepare 0.5N NaCl solution?

Weigh accurately 29.22 gm of NaCl and dissolve in 400 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 01 liter with distilled water, and properly mix it.

How to prepare 1N NaCl solution?

Weigh accurately 58.44 gm of sodium chloride and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare a 2N solution of pentahydrate sodium chloride?

Weigh accurately 29.22 gm of NaCl and dissolve in 200 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 250 ml with distilled water, and properly mix it.

How do you make a 1% solution of NaCl?

Weigh accurately 01.00 gm of sodium chloride and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 5% sodium chloride solution?

Weigh accurately 05.00 gm of NaCl and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare 10% sodium chloride solution?

Weigh accurately 10.00 gm of NaCl and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare a 100 ppm solution of NaCl?

In a volumetric flask, dissolve 10 mg of sodium chloride in 100 ml of distilled water to produce a 100 ppm stock solution.

How do you make a 1 ppm solution of sodium chloride?

Take 0.1 ml (100 microliters) from 100 ppm stock solution of sodium chloride and dilute it to 10 ml, the resulting solution has a concentration of 1 ppm.

How do you make a 10 ppm solution of sodium chloride?

Take 01 ml from 100 ppm stock solution of sodium chloride and dilute it to 10 ml, the resulting solution has a concentration of 1 ppm.

PRECAUTIONS:

• When working with chemicals, avoid contact with skin, eyes, clothing, ingestion, and inhalation.
• NaCl is hygroscopic in nature it should be stored in a tightly closed container.
• Stir a little amount of sodium chloride into a large volume of water at a time, and then dilute the solution.
• When making sodium chloride solutions, it is recommended that always use distilled water.
• Wear protective gloves, clothing, eye protection, and face protection.
• Wash your hands/skin thoroughly after handling.
• Solutions are highly alkaline and corrosive. Contact can cause serious skin and eye irritation. Therefore should be handled with care, follow laboratory safety measures (SOP/Procedure), and please use extreme caution when preparing the solution concentrations.

References:

1. Indian Pharmacopoeia : 1996
2. Wikipedia contributors. (2023, March 11). Sodium chloride. In Wikipedia, The Free Encyclopedia. Available Here: 
3. sWhat Is the Difference between Molarity and Normality? Westlab, Available Here:
4. Laboratory Solution Preparation, Available Here:

Preparation of copper sulphate solution

Learn how to make different concentrations of molar and normal copper sulphate solutions, which are needed for many applications such as research, practical, pharmaceutical, chemical laboratory, and industries, etc.

Copper (II) sulphate, more commonly referred to as copper sulphate, is an inorganic compound that has the formula CuSO4. It forms hydrates CuSO4•nH2O, where n can range from 1 to 7. Copper sulphate is manufactured by treating copper metal with sulfuric acid or copper oxides with sulfuric acid (H2SO4).

Copper sulfate is used as a drying agent and in several industrial applications. It is also employed in different chemical tests such as Fehling's, Benedict's, and Biuret reagents to test for proteins, and reducing sugars.

Generally, a solid form of copper sulphate (CuSO4•5H2O pentahydrate) in different-sized packs is supplied in the market by vendors in the form of blue (pentahydrate) crystals that are usually about 98% pure.

• The molecular weight of CuSO4•5H2O is 249.685 g/mol (pentahydrate)
• The melting point of CuSO4•5H2O is 560 °C
• The density of CuSO4•5H2O is 2.286 g/cm3
• The solubility of CuSO4•5H2O is: highly soluble in water and methanol but insoluble in ethanol and acetone.

Table of Contents: Preparation of 0.02M CuSO4 Preparation of 0.05M CuSO4 Preparation of 0.1M CuSO4 Preparation of 0.2M CuSO4 Preparation of 0.25 M CuSO4 Preparation of 0.5M CuSO4 Preparation of 1M CuSO4 Preparation of 2M CuSO4 Preparation of 1% CuSO4 Preparation of 2% CuSO4 Preparation of 5% CuSO4 Preparation of 10% CuSO4 Preparation of 20% CuSO4 Preparation of 100 ppm CuSO4 Preparation of 1 ppm CuSO4 Preparation of 10 ppm CuSO4

Requirements of glassware, chemicals, and apparatus:

Digital balance, beaker, pipette, pipette bulb, volumetric flask, measuring cylinder, glass rod, funnel, distilled water, AR/LR grade copper sulfate (CuSO4), etc.

Calculation method:

For example, we calculate how much weight of solid copper sulfate is needed to prepare a 0.1M solution in a 500 ml flask.

The following equation can be used to determine the molarity of a given solution:

Molarity=W/m×1000/V

Rearranging this equation to account for the weight necessary gives us,

W =Molarity × m × V/ 1000

Putting the given values in this equation,

W=0.5×249.685 ×500/1000 =62.42 gm

Therefore, to make a 0.1 N solution of copper sulphate, dilute 62.42 gm of CuSO4 in 500 ml of distilled water.

Note:

We have calculated the concentration based on CuSO4.5H2O (Pentahydrate) for preparing the solutions listed below.

How to prepare 0.02M CuSO4 solution?

Weigh accurately 04.99 g of copper sulphate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare a 0.05M CuSO4 solution?

Weigh accurately 06.24 gm of copper sulphate and dissolve it in 250 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 500 ml with distilled water, and properly mix it.

How do you make a 0.1 M copper sulfate solution?

Weigh accurately 24.97 gm of copper sulphate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare 0.2M CuSO4 solution?

Weigh accurately 49.94 gm of copper sulphate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare 0.25M Copper sulphate solution?

Weigh accurately 62.42 gm of CuSO4 and dissolve in 700 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 01 liter with distilled water, and properly mix it.

How to prepare 0.5M CuSO4 solution?

Weigh accurately 124.84 gm of CuSO4 and dissolve in 400 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 01 liter with distilled water, and properly mix it.

How to prepare 1M CuSO4 solution?

Weigh accurately 24.97 gm of copper sulphate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare a 2M solution of pentahydrate copper sulphate?

Weigh accurately 124.84 gm of CuSO4 and dissolve in 200 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 250 ml with distilled water, and properly mix it.

How do you make a 1% solution of CuSO4?

Weigh accurately 01.00 gm of copper sulphate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 2% CuSO4 solution?

Weigh accurately 02.00 gm of copper sulphate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 5% copper sulphate solution?

Weigh accurately 05.00 gm of CuSO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare 10% copper sulphate solution?

Weigh accurately 10.00 gm of CuSO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 20% solution of copper sulphate?

Weigh accurately 20.00 gm of CuSO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare a 100 ppm solution of CuSO4?

In a volumetric flask, dissolve 10 mg of copper sulphate in 100 ml of distilled water to produce a 100 ppm stock solution.

How do you make a 1 ppm solution of copper sulphate?

Take 0.1 ml (100 microlitres) from 100 ppm stock solution of copper sulphate and dilute it to 10 ml, the resulting solution has a concentration of 1 ppm.

How do you make a 10 ppm solution of copper sulphate?

Take 01 ml from 100 ppm stock solution of copper sulphate and dilute it to 10 ml, the resulting solution has a concentration of 1 ppm.

PRECAUTIONS:

• When working with chemicals, avoid contact with skin, eyes, clothing, ingestion, and inhalation.
• CuSO4 is hygroscopic in nature it should be stored in a tightly closed container.
• Stir a little amount of copper sulphate into a large volume of water at a time, and then dilute the solution.
• When making copper sulphate solutions, it is recommended that always use distilled water.
• Wear protective gloves, clothing, eye protection, and face protection.
• Wash your hands/skin thoroughly after handling.
• Solutions of CuSO4 are highly alkaline and corrosive. Contact can cause serious skin and eye irritation. Therefore should be handled with care, follow laboratory safety measures (SOP/Procedure), and please use extreme caution when preparing the solution concentrations.

References:

1. Indian Pharmacopoeia : 1996
2. Wikipedia contributors. (2023, March 7). Copper(II) sulfate. In Wikipedia, The Free Encyclopedia. Available Here:
3. What Is the Difference between Molarity and Normality? Westlab. Available Here:
4. Making Percent Solutions Of Chemicals, Available Here:

Preparation of KMnO4 solution

Learn how to make different concentrations of molar and normal potassium permanganate solutions, which are needed for many applications such as research, practical, pharmaceutical, chemical laboratory, and industries, etc.

In 1659, a German-Dutch scientist named Johann Rudolf Glauber was the first to find out that KMnO4 could be produced. Potassium permanganate is a manganese-based chemical compound derived from manganese dioxide. It does not occur naturally in its pure form but is present in many types of rocks in conjunction with oxygen, sulphur, and chlorine. It decomposes into oxygen when heated alone or with an alkali.

Potassium permanganate has the chemical formula KMnO4 and is an inorganic compound. It is a crystallized salt that has a purplish-black color, and when dissolved in water, it forms a solution that is highly pink to purple. It has many uses in the laboratory and chemical industry, as well as being used for the treatment of dermatitis, as a wound cleaner, and for disinfectant purposes.

Generally, a solid form of potassium permanganate (KMnO4) is supplied in different-sized packs is supplied in the market by vendors in the form of a purplish-colored, crystalline solid powder.

• The molecular weight of KMnO4 is 158.034 g/mol
• The melting point of KMnO4 is 240 °C
• The density of KMnO4 is 2.7 g/cm
• The solubility of KMnO4 is soluble in water, acetone, methanol, pyridine, etc.

Table of Contents: Preparation of 0.02M KMnO4 Preparation of 0.05M KMnO4 Preparation of 0.1M KMnO4 Preparation of 0.2M KMnO4 Preparation of 0.25 M KMnO4 Preparation of 0.5M KMnO4 Preparation of 1M KMnO4 Preparation of 2M KMnO4 Preparation of 1% KMnO4 Preparation of 2% KMnO4 Preparation of 5% KMnO4 Preparation of 7% KMnO4 Preparation of 10% KMnO4 Preparation of 20% KMnO4 Preparation of 100 ppm KMnO4 Preparation of 1 ppm KMnO4 Preparation of 10 ppm KMnO4

Requirements of glassware, chemicals, and apparatus:

Digital balance, beaker, pipette, pipette bulb, volumetric flask, measuring cylinder, glass rod, funnel, distilled water, AR/LR grade potassium permanganate (KMnO4), etc.

Calculation method:

For example, we calculate how much weight of solid potassium permanganate is needed to prepare a 0.1M solution in a 500 ml flask.

Let's first determine the molar mass (m) of KMnO4

K has a molecule weight of 40. The molecular weight of Mn is 54, and that of oxygen is 16. Here,

{{O} _ {4}} = 16X4=64

Thus, total – 40+54+64=158g

We have been given that, V = 500 ml, m = 158 g, M = 0.1M

The following equation can be used to determine the molarity of a given solution:

Molarity=W/m×1000/V

Rearranging this equation to account for the weight necessary gives us,

W =Molarity × m × V/ 1000

Putting the given values in this equation,

W=0.1×158×500/1000 =7.9 gm

Therefore, to make a 0.1 N solution of KMnO4, dilute 7.9 gm of KMnO4 in 500 ml of distilled water.

How to prepare 0.02M KMnO4 solution?

Weigh accurately 03.16 g of potassium permanganate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare a 0.05M KMnO4 solution?

Weigh accurately 7.9 gm of potassium permanganate and dissolve in 250 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water and properly mix it.

How to prepare 0.1M KMnO4 solution?

Weigh accurately 15.80 gm of potassium permanganate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water, and properly mix it.

How to prepare 0.2M KMnO4 solution?

Weigh accurately 31.60 gm of potassium permanganate and dissolve it in 500 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 1000 ml with distilled water and properly mix it.

How to prepare 0.25 molar potassium permanganate solution?

Weigh accurately 19.75 gm of KMnO4 and dissolve in 250 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 500 ml with distilled water, and properly mix it.

How to prepare 0.5M KMnO4 solution?

Weigh accurately 79.00 gm of KMnO4 and dissolve in 400 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 01 liter with distilled water, and properly mix it.

How to prepare 1M KMnO4 solution?

Weigh accurately 15.8 g of potassium permanganate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare 2M potassium permanganate solution?

Weigh accurately 79.00 gm of KMnO4 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, and properly mix it.

How do you make a 1% solution of KMnO4?

Weigh accurately 1.00 g of potassium permanganate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 2% KMnO4 solution?

Weigh accurately 02.00 gm of potassium permanganate and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 5% potassium permanganate solution?

Weigh accurately 05.00 gm of KMnO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 7% KMnO4 solution?

Weigh accurately 07.00 gm of potassium permanganate solid powder and dissolve it in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare 10% potassium permanganate solution?

Weigh accurately 10.00 gm of KMnO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How do you make a 20% solution of Potassium permanganate?

Weigh accurately 20.00 gm of KMnO4 and dissolve in 50 ml of distilled water in a volumetric flask. Once it has completely dissolved, make up the volume to 100 ml with distilled water, and properly mix it.

How to prepare a 100 ppm solution of KMnO4?

To make a 100 ppm stock solution, mix 10 mg of potassium permanganate with 100 ml of distilled water in a volumetric flask.

How do you make a 1 ppm solution of KMnO4?

Take 0.1 ml (100 microliters) of a 100 ppm stock solution and dilute it to 10 ml; the resulting solution has a concentration of 1 ppm.

How to prepare a 10 ppm solution of KMnO4?

Take 1 ml of a 100 ppm stock solution of potassium permangnate and dilute it to 10 ml; the resulting solution has a concentration of 1 ppm.

PRECAUTIONS:

• KMnO4 is hygroscopic in nature it should be stored in a tightly closed container.
• Stir a little amount of potassium permanganate into a large volume of water at a time, and then dilute the solution.
• When making potassium permanganate solutions, it is recommended that always use distilled water.
• Wear protective gloves, clothing, eye protection, and face protection.
• Wash your hands/skin thoroughly after handling.
• Chemical contact can cause serious skin and eye irritation. Therefore should be handled with care, follow laboratory safety measures (SOP/Procedure), and please use extreme caution when preparing the solution concentrations.

References:

1. Indian Pharmacopoeia : 1996
2. Wikipedia contributors. (2022, July 1). potassium_permanganate. In Wikipedia, The Free Encyclopedia. Available Here:
3. What Is the Difference between Molarity and Normality? Westlab. Available Here:
4. Making Percent Solutions Of Chemicals, Available Here:

Acetic acid in non aqueous titration

Non-aqueous titration is a type of titration in which the analyte is dissolved in a solvent that does not contain water. Non-aqueous titration is based on the same concepts (Bronsted-Lowry Theory) as acid-base titration, according to which an acid is a chemical that can give a proton to another substance, and a base is a chemical that can accept a proton.

Organic acids and bases that don't dissolve in water but do dissolve in non-aqueous solvents can be measured with non-aqueous titration. In non-aqueous titrations, you can use both potentiometric and indicator methods to find the endpoint.

Why is acetic acid used in nonaqueous titration?

Since it does not compete with weak bases for protons, acetic acid (Ch3COOH) is commonly employed in non-aqueous titration as a solvent/titrant. It can only be protonated by a strong acid, such as perchloric acid.

Which acid is useful in non-aqueous titration?

In non-aqueous titrations, the most commonly used acids are acetic acid and sulfuric acid which are protogenic solvents. Also, alcohols, which are amphiprotic solvents, are used in this type of titration.

Why is acetic anhydride used in non-aqueous titration?

In a non-aqueous (direct) titration, acetic anhydride is employed as a co-solvent, additive, or reagent to identify pharmaceutical compounds. It is a protogenic solvent, but it is more acidic and has a higher relative permittivity than acetic acid.

What is the purpose of adding glacial acetic acid?

A low concentration of oxonium ions forms when glacial acetic acid reacts with water. To overcome this problem, glacial acetic acid is dissolved with a non-aqueous solvent to form ions that have a high concentration.

Which is the most preferred solvent in nonaqueous titration?

In a non-aqueous titration, aprotic solvents such as benzene (C6H6), chloroform (CHCl3), carbon tetrachloride (CCl4), and acetone (C3H6O) are the most recommended solvents because they are chemically inert and that they are neither acidic nor basic.

Why is glacial acetic acid soluble in water?

As a polar molecule that can form a hydrogen bond with water, acetic acid is extremely soluble in water. Due to interactions between the polar -COOH group and polar water molecules it soluble completely soluble in water in all proportions.

Is glacial acetic acid a non-aqueous solvent?

Acetic acid is a type of hydrophilic protic solvent and can be used as a non-aqueous solvent. Acetic acid can dissolve both polar and nonpolar substances, and it can also be miscible with both polar and nonpolar solvents, like water, hexane, and chloroform.

What type of solvent is glacial acetic acid?

Acetic acid is the best organic solvent which is the type of hydrophilic protic solvent.

What is used as a titrant in nonaqueous titration?

In non-aqueous titrations of weak acids, the most common titrant that is used is lithium, sodium, and potassium methoxide.

Which indicator is used in aqueous titration?

The endpoint or equivalence point of non-aqueous titrations is identified using indicators such as methyl red, crystal violet, thymol blue, naphtholbenzein, etc.

Is acetic acid aqueous or liquid?

Acetic acid (CH3COOH), commonly known as ethanoic acid, is a simple monocarboxylic acid with two carbons that is mildly corrosive. It has an aqueous appearance, is odorless, and carries a pungent and strong vinegar smell.

Is acetic acid aqueous or organic?

Acetic acid is a type of organic acid that is the byproduct of sugar fermentation. It is also referred to as ethanoic acid, ethylic acid, methane carboxylic acid, etc.

Non-aqueous titration is required because weak acids and bases do not completely ionise when dissolved in water, but they become strongly acidic or basic, respectively, when a non-aqueous solvent is used. Because of this, it ionizes the provided organic or inorganic substance. As a result, a non-aqueous solvent is required for the full ionization of weak acids and bases.

Titration of organic bases with perchloric acid in anhydrous acetic acid is the most often used technique. Its nature causes it to ionise the provided organic or inorganic substance. Hence, a non-aqueous solvent is required for the full ionization of weak acids and bases.

Rather than water, different organic solvents can be used because they don't compete as well with the analyte for proton donation or acceptance. In this titration, four different types of solvents are used: aprotic (neutral), protophilic (basic), protogenic (acidic), and amphiprotic (protophilic and protogenic) solvent.

Why water is not used in non aqueous titration

Non-aqueous titration works on the same principles (Bronsted-Lowry Theory) as acid-base titration, according to which an acid is a chemical that can give a proton to another substance, and a base is a substance that can accept a proton.

We use non-aqueous titration to titrate organic acids and bases that are insoluble in water but soluble in non-aqueous solvents. Both potentiometric and indicator approaches can be employed to identify endpoint in non-aqueous titrations.

Why water is not used in non-aqueous titration?

Because water can act as a weak base and a weak acid, and so compete in proton acceptance or proton donation with other weak acids and bases dissolved in it. Therefore, titration using a medium that does not contain water is required.

The interference of water (H2O) molecules in the titration is the rationale for non-aqueous titrations. Dissolving bases and acids in water causes water molecules to compete with each other for proton donation and acceptance.

So, a titration method that doesn't involve water molecules is needed. To determine substances, a process known as non-aqueous titration uses non-aqueous solvents. Four different types of solvents can be used in a non-aqueous titration that is aprotic, protophilic, amphiprotic protogenic, and solvents. Alcohols, glacial acetic acid, chloroform, acetonitrile, and ammonia, are a few examples of non-aqueous solvents.

Commonly asked questions on non-aqueous titration are as follows:

What should be avoided in non-aqueous titration?

In a non-aqueous titration, moisture should be avoided so that the solution can be neutralized and the right endpoint can be found.

Which titration does not contain water as a solvent?

Non-aqueous titration is a type of titration in which water is not included as the solvent but rather the analyte is dissolved in a non-aqueous solvent.

Which indicator is used in non-aqueous titration?

In non-aqueous titrations, indicators such as methyl red, crystal violet, thymol blue, naphtholbenzein, etc. are used as indicators to determine the endpoint or equivalence point of the titration.

Factors affecting non aqueous titration

Non-aqueous titration is the titration of analytes that are weakly acidic or basic in the absence of water. A non-aqueous solvent is used to dissolve the solute, which is then titrated with an acid or base titrant.

Both acid-base titration and non-aqueous titration work on the same basic principle (Brønsted-Lowry Theory). According to this, a base donates a proton to another chemical, and a base accepts a proton.

The interference of water molecules in the titration is the rationale for non-aqueous titrations. Water is both a weak acid and a basic. When different bases and acids are dissolved in water, the water molecules compete with each other for proton donation and acceptance. Accordingly, a titration method that does not involve the interference of water molecules is necessary; as a result, non-aqueous solvents are used in a procedure known as non-aqueous titration to assess compounds.

In a non-aqueous titration, there are four types of solvents that are used. These are aprotic solvents, protogenic solvents, protophilic solvents, and amphiprotic solvents. Some examples of non-aqueous solvents are glacial acetic acid, ether, acetonitrile, nitrogen tetroxide, alcohols, carbon disulphide, benzene, chloroform, acetone, formic acid, ammonia, etc.

Crystal violet indicator, methyl red indicator, naphtholbenzein indicator, quinaldine red, thymol blue, etc. are used as indicators for non-aqueous titrations to detect the endpoint/equivalence point of the titration. Depending on the nature of the titrant, each indicator has a distinct color change at the end of the reaction.

Factors that affect non-aqueous titration:

• Temperature: The volume of non-aqueous solutions used is affected by temperature, which causes the concentration of the sample to fluctuate. Temperature affects non-aqueous solvents because they expand more than water.
• Highly acidic or basic condition: In the process of titrating weak bases or acids, the addition of very acidic or basic solvents raises the level of acidity or basicity, which increases the consumption of titrant.
• Moisture level: When doing non-aqueous titrations, it is important to stay away from moisture in order to neutralize the solution and make the endpoint more accurate.
• Acid-base characteristics of the solvents used: In a non-aqueous titration, the end-point is affected by the acid-base characteristics of the solvents used.
• Protolysis of the substance: The endpoint of the reaction may increase due to the protolysis of the substance.
• Dielectric constant: Solvents with low dielectric constants are often used in non-aqueous titrations, which produce sharp endpoints.
• Carbon dioxide: The endpoint of acid-base titrations can be affected when carbon dioxide (CO2) from the air dissolves in water and forms carbonic acid, so it should be controlled.

Preparation of universal indicator solution

Learn the procedure for making a universal indicator solution.

A universal indicator is a pH indicator made up of different indicators or dyes that changes color over a wide range of pH values to indicate the acidity or alkalinity of the sample solution.

When a sample of the acid or base solution is added to the universal indicator, a new color is produced, which can then be compared to the colors on a pH chart to determine the solution's pH value. On the pH scale, values range from 0 to 14.

Requirements:

Phenolphthalein (C20H14O4), methyl red (C15H15N3O2), methyl orange (C14H14N3NaO3S), bromothymol blue (C27H28Br2O5S), thymol blue (C27H30O5S), ethanol, and distilled water are the chemicals needed to make a universal indicator.

How to prepare universal indicator solution:

• Weigh accurately 0.1 gm of phenolphthalein, 0.3 gm methyl orange, 0.2 gm methyl red, 0.5 gm thymol blue, 0.4 gm bromothymol blue, and pour it into a 500.00 ml volumetric flask and dissolved in a mixture of 250 ml ethanol and 250 ml water.

The universal indicator is most commonly used in research laboratories, as well as in school and university laboratories. The majority of universal indicators on the market are modified versions that are very close to the original patented formula developed by scientist Yamada in 1933.

A universal indicator can be in the form of paper or as a solution; however, they have different uses.

Universal indicator color range:

pH Range	Type	Colour produce
< 3	Strongly acidic	Red
3 to 6	Weakly acidic	Orange to Yellow
7	Natural	Green
8 to 11	Weak alkali	Blue
> 11	Strong alkali	Indigo to Violet

How to use universal indicator:

• Universal indicator paper:

A drop of the solution to be tested is placed on a strip of universal indicator paper, and the paper changes color depending on the pH of the sample.

• Universal indicator paper solution:

Using a pipette or dropper, add a few drops of universal indicator to your sample. The color of the solution will change based on the pH of the sample.

Precautions while using the universal indicator:

• Always wear personal protective equipment, such as an apron, goggles, gloves, etc. when working in the lab.
• Keep away from any source of heat, spark, or flame.
• Avoid getting touch this substance on your skin, in your eyes, as well as by ingestion it.
• Always keep the universal indicator solution in a container that is airtight and tightly closed.
• When you leave work, wash your hands and any other exposed areas with gentle soap and water.

References:

1. Universal indicator. (2022). In Wikipedia, Available Here
2. Theory_of_indicators_Ostwalds_theory.pdf, Available Here
3. Learn How to Prepare Useful Acid-Base Indicators, Available Here