Category: Chemistry Notes PPT

Herpes disease is caused by herpes virus and can be cured by the drugs containing lysine. Lysine is an essential amino acid for the human body. Lysine is not only used in the treatment of herpes but for various other diseases as well. It also has many culinary applications. In this article we will discuss chemical aspects of lysine, its structure, sources and uses. 

What is Lysine? 

Lysine is an essential -amino acid which is found in many foods as protein. Its symbol is Lys or K. As we know amino acids are the basic structural units of protein, so Lysine is used in the synthesis of proteins. As it is an [alpha] – amino acid so, it contains [alpha] – amine group and [alpha] – carboxylic acid group. We will discuss its structure in detail in the next section. 

It is essential for our body, but our body cannot synthesize it on its own. So, it must be obtained from foods. Lysine helps in animal growth as well. That’s why Lysine supplements are used as animal feed, specially for chickens and pigs for their optimal growth and production of meat. Some plants and bacteria can synthesize lysine from aspartic acid which is also an amino acid. It is synthesized in organisms by mainly following two biosynthetic pathways –

It was 1st isolated in 1889 by German Chemist Ferdinand Heinrich Edmund Drechsel from the casein phosphoprotein present in milk. Ferdinand Heinrich named lysine as ‘Lysin’. After almost thirteen years of its discovery and isolation, lysine was synthesized in 1902 by German Chemists Emil Fischer and Fritz Weigert. They determined the structure of the lysine as well. 

As lysine is vital for many biological processes so its deficiency can cause many diseases such as anaemia, defects in tissues, protein energy deficiency etc. It is a vital organic compound for growth of plants and animals as well. Thus, lysine is an important – amino acid for various processes occurring in human beings, animals and plants as well. 

Structure of Lysine 

Lysine contains [alpha] – amine group (In form of protonated -NH3+), [alpha] – carboxylic acid group (In form of deprotonated -COO–), and a lysyl side chain [(CH2)4NH2] in its carbon chain. It is a covalent organic compound. It is encoded by the genetic codes AAA and AAG. It has a chiral [alpha] – carbon. Its enantiomer L – Lysine in which [alpha] – carbon is in the S configuration and is biologically active.  

(Image to be added soon)

Amino Acid Structure 

[alpha] – Carbon, amino group and carboxylic acid group are the backbone of lysine. Its chemical formula is C6H14N2O2. It is a linear amino acid molecule. Lysine is a base and water soluble. It forms hydrogen bonds with other molecules. Its structure formula L-lysine is given below –

(Image to be added soon)

Structure of L- Lysine

General Structure of lysine –

(Image to be added soon)

Foods Rich in Lysine or Sources of Lysine 

Lysine is essential for proper growth and is used in biosynthesis of protein. As you know, lysine cannot be synthesized by our body and we must take it through diet. So, it becomes necessary for us to include lysine rich foods in our diet. As lysine is used in biosynthesis of proteins, so it naturally occurs in protein rich food items. 

Meat (red meat), eggs, rajma, chickpeas, few species of fishes, soybeans, tofu, fenugreek seeds, cheese, pork, chicken etc. are good sources of lysine. Other beans, dairy products and Brewer’s yeast, mushroom also contain lysine. 

Apart from these natural sources of lysine various other lysine supplements are also available. It is available in the form of tablets, capsules, creams and liquid solution form. 

Function of Lysine 

Lysine is necessary for the healthy functioning of the human body and some organisms, plants and animals. Catabolism of lysine takes place in the liver. Amino acids of lysine provide glucose to the human body through metabolism. It is metabolized into acetyl – CoA which forms adenosine triphosphate. Adenosine triphosphate is the currency of energy in our body. Lysine plays a vital role in the citric cycle in animals. 

Allysine is a derivative of lysine which is used to produce collagen and elastin. These are essential for skin, joints etc. 

Uses of Lysine 

Lysine plays an important role in many biological processes. Its most common role is proteinogenesis. It is a base of protein structure. It is considered as amphipathic which means it shows both hydrophilic and lipophilic properties. Because of this it becomes even more important for various processes. Its amino group forms hydrogen bonds, covalent bonds and salt bridges with other molecules. Therefore, lysine contributes to protein stability as well. Lysine plays a major role in epigenetic regulation. Many histone modifications involve lysine. These modifications can affect gene regulation. 

Lysine plays a key role in calcium homeostasis and fatty acid metabolism. It is involved in the crosslinking of helical polypeptides in collagen. It is a precursor for carnitine. Carnitine transports fatty acids to the mitochondria. 

Lysine is useful in treatment of herpes. Herpes is caused by herpes simplex virus. Arginine promotes the growth of herpes simplex virus and lysine blocks the activity of arginine. 

It helps the body to absorb calcium. As calcium is a must for healthy bones. So, researches show that lysine helps in prevention of osteoporosis. 

Sometimes athletes take lysine supplements as protein supplements as studies show that lysine helps muscles to recover faster after stress. 

Lysine is used as animal feed as it helps in their optimal growth. Thus, lysine is a key ingredient of food, which is used in poultry farms, pig farming etc. to feed chickens, pigs and other animals for their optimal growth and high – quality meat. 

Early studies show that lysine is effective in treatment of canker sores and diabetes. Studies state that it can even prevent canker sores and diabetes. It reduces the blood sugar level. Lysine is helpful in reducing the stress as well. 

A derivative of lysine is used in pain management as it serves as an anti – inflammatory agent. It can be helpful in preventing cardiovascular diseases and blood pressure fluctuations. 

Deficiency of Lysine 

As lysine plays key roles in many biological processes and essential for our body, so its deficiency causes various diseases also. Most of the diseases due to lysine are the result of downstream processing of lysine. Lack of lysine causes disease related to connective tissues. Lack of lysine may cause lack of carnitine levels in the body which may cause many health – related issues as carnitine transfers fatty acids to mitochondria and mitochondria is known as powerhouse of the cells. Deficiency of lysine may cause anaemia, protein energy malnutrition, neurological disabilities, epilepsy, ataxia and psychomotor impairment.  

This ends our coverage on the topic “Lysine”. We hope you enjoyed learning and were able to grasp the concepts. We hope after reading this article you will be able to solve problems based on the topic. If you are looking for solutions of NCERT Textbook problems based on this topic, then log on to website or download Learning App. By doing so, you will be able to access free PDFs of NCERT Solutions as well as Revision notes, Mock Tests and much more.

The formula MnO2 is commonly known as Manganese Dioxide. It is a solid that has a black-brownish colour. Manganese dioxide, when found in nature, is known as pyrolusite. It is considered to be the most plentiful out of all the manganese compounds. Pyrolusite is the principal ore of the compound manganese dioxide. Manganese Dioxide is commonly used for batteries and also as pigment for other Manganese compounds. An impure form of manganese can be obtained by reducing manganese dioxide with carbon. Manganese Dioxide is the inky quadra positive manganese compound. 

MnO2 compound name is given as dioxo manganese. It is a certain MnO2 chemical name. 

Where is Manganese Dioxide Found?

The most common Manganese bearing minerals are Pyrolusite and Rhodochrosite. These are the basic sources of manganese dioxide in nature. Moreover, manganese dioxide and the other manganese compounds are found on the ocean floors too. The countries which supply the maximum Manganese are Brazil, USSR, Russia, India, Africa, Australia and New Zealand. The primary way in which manganese is produced is by the reaction of the oxides with sodium, aluminium and magnesium. Chemically in the laboratories, it is produced by electrolysis. Manganese is present in four different forms. One form is stable in room temperature and is known as alpha form. 

Chemical Properties of Manganese Dioxide 

Chemical Formula: MnO2

Molar Mass: 86.9368 g/mol

Appearance: Brown – black solid

Density: 5.026 g/cm3

Manganese Dioxide Melting Point: 535 °C

Covalently Bonded Unit: 1

Solubility in Water: Insoluble 

Physical Properties of Manganese Dioxide

Odour: Odourless 

Appearance: Brown – Blackish solid

Complexity: 18.3 

MnO2 Oxidation Number: +4

Solubility: Insoluble in water 

Hydrogen Bond Acceptor: 2

Properties of Manganese Dioxide

• Magnesium dioxide is abundantly used in the ceramic industry. All the raw materials used in the making of glass contain some amount of iron. This iron is usually in the form of ferric oxides. The use of manganese dioxide in such industries is highly beneficial and practical. 

• Manganese ores are again commonly used in dry cell batteries. Many of these cells need to be activated by physical or chemical means. These means are manufacturing techniques that need special machinery and work at certain temperatures only. 

• Glass often gets a tint due to the presence of impurities. Manganese dioxide gets rid of the green tint produced as a result of the various iron impurities. 

• The positive electrode carbon in batteries is secure indeed by a layer of magnesium dioxide. Carbon is also present around It. 

• A majority of manganese dioxide is used in the steel industry. Manganese is basically used in the deoxidation of steel. 

• The black-brown pigments present in paint are basically manganese dioxide. 

• Soft drink cans also have a specific alloy present in them. This alloy is made from manganese dioxide. 

Solved Examples: 

Manganese Dioxide as a Catalyst:

Oxygen is produced in the laboratory in the presence of hydrogen peroxide and manganese dioxide. Manganese dioxide here acts as a catalyst and accelerates the reaction. 

2H2O2(aq) → 2H2O(l) + O2(g)

Here manganese dioxide is the accelerant. When manganese dioxide is added to hydrogen peroxide, bubbles of oxygen are produced. 

3MnO2 (s) + 4Al (s) → 3Mn (I) + 2Al2O3 (s)

Manganese Dioxide Reacting With Potassium Chlorate

Potassium chlorate (KClO3) is heated in the presence of manganese dioxide catalyst and it decomposes to form potassium chloride and oxygen gas. 

The balanced chemical equation is: 

2KClO3 → 2KCl + 3O2

The above is the laboratory process of oxygen generation. The chemically produced oxygen is suitable for usage immediately. It has to go through a few more filtration processes. 

Manganese Dioxide Reacting With Aluminium

Manganese dioxide , when reacted with aluminum, gives metallic manganese and aluminum oxide. Along with this, a lot of heat is generated. It is an exothermic reaction as the change in enthalpy comes out to be negative. 

MnO2 + Al → Al2O3 + Mn 

Fun Facts About Manganese and Manganese Dioxide

• Manganese was first discovered in the year 1774. 

• Historically it has been seen that cave paintings in the Stone Age contained manganese pigments. 

• Manganese has a very prevalent look to that of iron. In contrast to Iron it has a silver – grey colour. 

• It Is well known that iron rusts the most, but Manganese rusts as much as iron only. In fact research has shown that at times, manganese rusts more than iron too sometimes. 

• Manganese dioxide is present abundantly In nature. 

• The most common uses of manganese dioxide are production of stainless steel, glass industry, paint industry and more. 

• Manganese is found in the mitochondria for functioning of living cells. Mitochondria, also known as the powerhouse of the cell, depends on manganese for proper functioning of the human cell body. 

• Most of the manganese Is present in the skeleton of the human body. 

• Although manganese is not toxic in a light amount, a handful of manganese usage can prove to be lethal.

What are Metal Carbonyls?

Metal Carbonyls can be defined as compounds that are volatile and have low melting points. They are made from the compound of Mx(Co)y that decomposes into carbon monoxide and metal on heating. They can be toxic when in contact with skin. They can also be toxic if inhaled or ingested due to their property of carbonylate haemoglobin which converts it into carboxyhemoglobin that further prevents the binding of oxygen in the blood cells. Furthermore, in a metal carbonyl, both characters, σ, and π, are possessed by the metal-carbon bond. This bond is further strengthened by the synergic effect produced by the metal-ligand bond. 

Metal Carbonyls and Their Structure

When learning about metal carbonyls, it is important to study their structure as well. One of the unique properties of metal carbonyls is that they exist in two types of bonding. The first kind exists when there is a donation of electrons by the carbonyl molecules to the vacant orbitals of the metal, thereby forming a metal-carbon σ bond.

The second type is when there is a donation of a pair of electrons from a filled d orbital metal into the vacant anti bonding π* orbital of a carbonyl ligand. This way a metal-carbon π bond is formed. The 18-electron rule is generally used in predicting the stability of metal carbonyls. According to this rule, the electrons are gained from the ligands by the metal atom to reach the nearest noble gas configuration.

What Are Metal Carbonyls Organometallics?

Metal Carbonyl Organometallics can be defined as compounds that consist of at least one metal-to-carbon bond. Moreover, the carbon in the metal-to-carbon bond is part of an organic group. The organometallic compounds play a major role in the development of the science of chemistry. 

An example of an organometallic compound is ferrocene in which an iron atom is in between two hydrocarbon rings. There are great variations amongst the physical and chemical properties of organometallic compounds. Most of them are solid, specifically those with ring-shaped hydrocarbon groups. 

Some organometallic compounds are present both in liquid and gaseous states. They can also be flammable, particularly the compounds of electropositive elements such as lithium, aluminium, and sodium. Major organometallic compounds are highly toxic and volatile. Some common examples of organometallics are Grignard Reagent – RMgX, Gilman Reagent – R2CuLi, Dimethylmagnesium – Me2Mg, Triethylborane – Et3B, Ferrocene, Cobaltocene. 

Properties of Metal Carbonyls Organometallics

The 18-electron rule followed by metal carbonyl is surprisingly not followed by metal carbonyls organometallics. Some other basic properties of metal carbonyl organometallics are specified below:

• Organometallics are not soluble in water

• Instead, they are soluble in ether

• Metal Carbonyls Organometallics has a relatively low melting point

• Another interesting property of organometallics is their electronegativity. While metals have a lower electronegativity of 20, the organometallic carbon compound has an electronegativity of 2.5.

• Organometallic compounds are also highly reactive. That is the reason why they are generally kept in organic solvents.

Uses of Metal Carbonyl Organometallic

The discovery of organometallic compounds has led to their application in various fields. Some of the popular uses of organometallics are specified below:

• The most common use of organometallic compounds is as a reagent.

• Organoarsenic compounds are also used in the treatment of a common sexually transmitted disease called syphilis. 

• Grignard reagent, which is a popular organometallic compound is used for various purposes such as in the synthesis of a secondary alcohol, aldehydes, etc. 

• Another use of organometallic is as an additive

• They are also useful for various industrial purposes. 

• Cis-plastin, an organometallic compound, is used as an anticancer drug

• For hydrogenation alkenes, Wilkison’s catalyst is used

Micas are a category of minerals with one distinguishing physical property: individual mica crystals can be easily broken into incredibly thin elastic plates. This characteristic can be defined as a perfect basal cleavage. It is common in metamorphic and igneous rock and is occasionally found as small flakes in sedimentary rock. It is specifically prominent in several pegmatites, schists, and granites of mica many feet across have been found in some of the pegmatites.

General Considerations

Out of 28 known species of the mica group, only 6 of them are common rock-forming minerals. Muscovite, which is the common biotite and light-coloured mica, typically black or nearly so, are the abundant ones. Phlogopite, which is typically paragonite, and brown is macroscopically indistinguishable from the muscovite. They are also fairly common. Lepidolite, in general, pinkish to lilac in colour, takes place in lithium-bearing pegmatites.

Glauconite, which is a green species that doesn’t contain similar general macroscopic characteristics to other micas, takes palace sporadically in several marine sedimentary sequences. Except for glauconite, all of these micas easily exhibit observable perfect cleavage into the flexible sheets. Glauconite occurs most often as pellets like grains, containing zero apparent cleavage.

Chemical Compositions

Few of the natural micas contain end-member compositions. For example, most of the muscovites have sodium substituting for some potassium, and diverse varieties contain vanadium or chromium or a combination of both aluminium’s replacing parts; furthermore, the Si: Al ratio can range from the indicated 3:1 up to up to 7:1.

The same variations in composition are well-known for other micas. As a result, much like other mineral groups (for example, garnets), different individual parts of naturally occurring mica specimens have different amounts of perfect end-member compositions.

Crystal Structure

Micas contain sheet structures whose basic units have two polymerized sheets of silica (SiO₄) tetrahedrons. Two of these sheets can be placed next to each other with their tetrahedron vertices pointed in the same direction; the sheets are cross-linked by the cations. For example, aluminium in hydroxyl and muscovite pairs complete the coordination of these cations. 

As a result, the cross-linked double layer can be tightly bound, has the bases of the silica tetrahedron on each of its outer faces, and is negatively charged. This charge is balanced by the singly charged large cations. For example, potassium, present in muscovite, which joins the cross-linked double layers to produce the complete structure. The differences among the mica species are based upon differences in the X and Y cations.

Origin

Micas can originate as the result of diverse processes under many various conditions. Their occurrences include crystallization from the consolidating magmas, deposition by the fluids, which are derived either from or directly associated with the magmatic activities, deposition by fluids circulating during both regional and contact metamorphism, and formation as the result of the processes of alteration, perhaps even those, which are caused by the weathering, that involve minerals like feldspars.

Micas’ stability ranges have been studied in the field, and in some cases, their presence (rather than their absence) or some part of their chemical structure may function as geobarometers or geothermometers.

Occurrence of Mica

Mica can be distributed widely and takes place in metamorphic, sedimentary, and igneous regimes. Large crystals of mica, which are used for multiple applications, are typically mined from the granitic pegmatites.

The single crystal of mica (phlogopite), which is the largest documented, was found in Lacey Mine, Canada, Ontario; it is measured as 10 m × 4.3 m × 4.3 m and weighing up to 330 tonnes. The same-sized crystals were also found in Russia and Karelia.

Flake and scrap mica can be produced all over the world. The primary producers of mica as of 2010 were found to be: Finland (68,000 tons), Russia (100,000 tons), South Korea (50,000 tons), United States (53,000 tons), Canada (15,000 tons), and France (20,000 tons). The total production was 350,000 tons globally, although there is no reliable data available for China. Most of the sheet mica was formed in Russia (1,500 tons) and India (3,500 tons).

Flake mica is found in a variety of places, including metamorphic rock known as schist, as a byproduct of the mining of kaolin and feldspar resources, placer deposits, and pegmatites. Considerably, sheet mica is less abundant than scrap and flake mica, and it is recovered occasionally from the mining flake and scrap mica. The important sources of the sheet mica are given as pegmatite deposits. Sheet mica prices differ by grade, ranging from under $1 per kilogramme for low-quality mica to ＄2,000 or more per kilogram for high-quality mica.

In India and Madagascar, it is also artisanally mined in poor working conditions and with child labour help.

Use of Mica

Micas can be used in a wide range of products ranging from paints, drywalls, fillers, especially in automobile parts, shingles and roofing, electronics, and more. The mineral can also be used in cosmetics to add “frost” or “shimmer.”

Everything that surrounds us is composed of millions and millions of tiny particles, known as atoms. While these are invisible to the naked eye, they are the fundamental building blocks of this universe. Studying these substances and how their composition plays a vital role in our everyday existence is a very important part of applied sciences. 

The mole concept comes into play when we talk about atoms and their properties. 

What is a Mole? 

To introduce the concept of a mole, first, we will talk about the Avogadro’s number/constant which is equal to 6.02214076 × 10²³. 

When we talk about the number of moles of a substrate we divide the number of total particles of a molecule/compound/atom by Avogadro’s constant.

Hence, 6.02214076×10²³  molecules of an oxygen molecule (O₂) will constitute one mole of oxygen & similarly 6.02214076×10²³ atoms of carbon will constitute one mole of carbon. In other words, when we say one mole of a substance is present in a sample that means that 6.02214076×10²³ number of that specific element is present in the sample. 

Therefore, a mole is a unit just like kilograms or centimetres, which refers to the specific measure of how many atoms or molecules are contained in a substance. 1 mole of one element contains the same quantity of atoms as 1 mole of any other element. However, the mass of 1 mole is different for every element. 

What Do We Understand by Molar Mass? 

The molar mass of an element means the total mass of one mole of that element. Relative molar mass refers to the smallest mass unit of any compound in comparison to one-twelfth one of the mass of one Carbon-12 atom. This means that the number of atoms that are present on 12 grams of one Carbon-12 atom is the same as the number of moles present in one mole of it. 

Using a mass spectrometer, it has been found that the mass of a Carbon-12 atom is 1.992648×10^-23 g. In any element, the total number of sub-particles present, such as atoms and molecules, is collectively referred to as one mole.

Atomic mass strictly refers to the mass of one single atom of an element and is expressed in Atomic Mass Units (u). 

One atomic mass unit =1.9944235 × 10^-23 g

One molar mass of an element would be the mass of one mole of that element’s atoms.

So numerically, one molar mass = mass of (6.02214076×10²³ * Atomic mass of that element).  

What Do We Understand by Molecular Mass? 

This term is used to refer to the mass of a single molecule of any given compound or element. The molecular mass of an element or a compound is calculated by first calculating the number of atoms that are bonding in the molecules and adding that with the respective atomic mass units. 

Molecular mass is denoted by Daltons (Da), where 1 Da is equal to 1 u. 

What is Mole Fraction?

Mole fraction is also a method to express the concentration of a substance in a mixture. Of a solution mixture containing different elements in different quantities, we express the concentration of a specific element(X) by dividing the number of its moles present by the total number of moles that includes the number of moles of other constituents and the moles of (X) included. 

Mole fraction of solute = Moles of Solute/ Moles of (solute + solvent) 

Mole fraction is just a ratio and is hence dimensionless.

Percentage Composition

Another indicator of concentration, percentage composition also depicts the proportion contributed to the total mass of a mixture by its mass. The formula for percentage composition is given by:

Percentage composition = (Mass of the individual component/mass of the mixture) * 100.

Taking Methane as an example, methane’s percentage composition is  74% carbon and 25% hydrogen, though there are more hydrogen atoms. 

What Does Relative Molecular Mass Indicate? 

To understand this, it is first important to know what relative atomic mass refers to. This simply means having a single and uniform atomic mass for elements that may have many different isotopes, such as Carbon. The relative atomic mass of an element can be found out by calculating the average of the weighted isotope mass, as per their frequency. 

Therefore, the relative molecular mass refers to the total relative atomic masses of all the elements that are present in one compound. 

Molarity Meaning

Molarity is a very common indicator of concentration in which we determine the number of moles of a chemical species (solute) that has been dissolved in a liter of solvent. To determine Molarity we first find out the number of moles that are present inside the solution. 

We go about it by dividing the quantity of a substance that has been dissolved in 1 L of solvent and dividing it by the molar mass of that substance which will give us the Molarity.

Have you ever stepped into an elderly person’s closet and detected a peculiar and pungent odor right away? It’s a distinct smell that younger generations aren’t familiar with, as the substance that emits it has been phased out in recent years. You may wonder what’s causing the odor. It’s known as mothballs. Mothballs were used in clothes as a fumigant to prevent moths and other insects from destroying the textiles.

Naphthalene, a polyaromatic hydrocarbon, is the primary ingredient in conventional mothballs. Polyaromatic denotes the presence of more than one benzene ring, while hydrocarbon denotes the presence of only carbon and hydrogen atoms. Today, we’ll hear about naphthol, a naphthalene derivative. Naphthol is very similar to its parent compound, naphthalene, with the exception of the hydroxyl (-OH) group. Let’s take a look at some of this molecule’s main features together!

Amino Naphthol

Naphthol is one of two colorless, crystalline organic compounds derived from naphthalene and belonging to the phenol family; the molecular formula for both is C10H7OH. Both compounds have long been associated with the production of dyes and dye intermediates, but they also have significant applications in other industries.

The compound 1-naphthol, or alpha naphthol, is used directly in some dyes and is converted to compounds that are eventually integrated into other dyes. Heating 1-naphthalenesulfonic acid with caustic alkali or heating 1-naphthalene amine with water under pressure produces it.

The compound 2-naphthol, also known as b naphthol, is the most common naphthalene-based chemical intermediate. It’s made by combining 2-naphthalenesulfonic acid and caustic soda, and it’s used to make a variety of dyes and dye intermediates, as well as tanning agents, antioxidants, and antiseptics. It has been shown to cause cancer.

Structure

A hydroxyl group is bonded to a naphthalene ring to form naphthol. 1-naphthol and 2-naphthol are two isomers of naphthol (compounds with the same chemical formula but different atom connectivity). The hydroxyl group is bound to a different carbon in the naphthalene ring in the two isomers.

Aromaticity is another significant structural characteristic of naphthol. It has alternating double and single bonds in its rings, which is typical of aromatics.

Polarity

Since it comprises a hydroxyl group, naphthol is a strongly polar molecule, with the oxygen atom attracting electron density to itself through the bonds. A difference in electronegativity (an atom’s ability to attract electrons) between one or more atoms is needed for a molecule to be polar, and oxygen is more electronegative than both carbon and hydrogen in the case of naphthol. As a result, it can ‘hog’ more electron density in the form of bonds, causing it to become polar.

Solubility

Naphthol is very flexible in terms of the solvents it is soluble in (things in which it can form solutions). It can make a hydrogen bond with other alcohol-based (polar) solvents including ethanol, methanol, and isopropanol due to the presence of the hydroxyl group. Because of its ability to form hydrogen bonds, it is easily soluble in these types of solvents.  

Alcoholic Alpha Naphthol

Molisch’s test is a biochemical test for detecting the presence of carbohydrates in solution, named after the Austrian chemist H. Molisch (1856–1937), who invented it. A small amount of alcoholic alpha-naphthol is applied to the test solution, followed by a gradual pour of concentrated sulphuric acid down the test tube’s rim. The creation of a violet ring at the junction of the two liquids indicates a positive reaction.

Pyridylazo Naphthol

The orange dye pyridylazo-2-naphthol (PAN) is widely used as an acid-base indicator. Since it can form chelates with metal ions, it’s a good indicator for complexometric titrations. PAN may also be used as a spectrophotometric reagent to remove metal chelates from an organic solvent.

Furfural and 1 Naphthol

The rapid furfural test is similar to Molisch’s test, except that concentrated hydrochloric acid is used instead of concentrated sulfuric acid, and the solution is boiled. To ethanolic 1-Naphthol and concentrated hydrochloric acid, a dilute sugar solution is added.