Category: Chemistry Notes PPT

This article primarily deals with the structural and chemical formula of potassium hydroxide. Potassium hydroxide or as it is commonly termed caustic potash is one of the most important inorganic compounds and just like sodium hydroxide (NaOH), it is also a prototype strong base. Due to the basic and caustic properties, it has vast applications in the Industries. Potassium hydroxide is one of the most important and only prosecutor in many liquid soap solutions as well as many potassium-based chemicals. Therefore in 2005, the total production of potassium hydroxide was about 700,000 to 800,000 tons. Thus it is very important to learn the potassium hydroxide formula (known commonly as caustic potash formula). It is one of the organic compounds that is having a vast range of applications in almost all chemical industries. 

Chemical Formula of Potassium Hydroxide

The potassium hydroxide formula, commonly known as caustic potash formula is represented as KOH. It is predominantly an ionic compound. If the caustic potash formula is broken into two components with one hydroxyl anion [OH[^{-}]] that has a single negative charge on it and potassium ion [K[^{+}]] with one positive ion, thus the charge ratio becomes 1:1 and thus one potassium ion makes a stable bond with one hydroxyl ion. The synthesis of potassium hydroxide is very similar to that of sodium hydroxide in the industrial process which is known as the chloralkali process. The process follows the electrolysis of potassium chloride that produces potassium hydroxide, which is the chemical name of caustic potash with the release of chlorine gas as a by-product. Now by looking at the chemical formula of caustic potash that is KOH, the K-O bond is ionic due to the high electronegativity but the O-H bond in this case is covalent even when the electronegative difference is high. It is because after making the ionic bond by charge transfer with potassium, oxygen possesses more negative charge and as charge separation requires a lot of energy thus the ionization of H-O is not possible as the first ionization with K-O already happened. It is because the second ionization needs more energy for charge transfer than the first ionization due to high charge density. therefore, in the chemical formula for potassium hydroxide the K-O bond is ionic but the O-H bond is covalent.

Structural Formula of Potassium Hydroxide 

The KOH molecule in its solid-state crystallizes at a higher temperature and form a similar structure to NaCl. The KOH crystallizes in the monoclinic space group of C[_{2}^{2}]ーP2[_{1}]. The dimension of the two molecules in a molecular cell is a = 3.95, b = 4.00, c = 5.75, 𝛃 = 103.6[^{0}]. The OH[^{-}] ion is an effectively spherical anion whose radius is measured equal to 1.53 Å that falls between Cl[^{-}] and F[^{-}] cations. This spherical radius is due to the randomly or rapidly disordered hydroxyl ion. At room temperature, where the hydroxyl (OH[^{-}]) ion is completely in order the K[^{+}] ion centres are distorted, thus making the KOH bond length (depending on the orientation of hydroxyl ion) ranging from 2.69 to 2.15 Å. Also, each of the potassium ion centres is surrounded by an octahedron of oxygen atoms that are distorted. The oxygen atoms form a zigzag chain on the plane of the b-axis and according to the advanced stoichiometric arrangement the hydrogen atoms either lie on or nearby the zigzag chain of oxygen atoms that is very close or exactly linear in nature. Thus breaking of this hydrogen bond will lead to the formation of KOH cubic structure at high temperature. Therefore the molecular formula of potassium hydroxide is structurally represented as follows. 

The cubic structure of solid KOH is as follows.

Properties of Potassium Hydroxide

Some of the important physicochemical properties of KOH are listed below.

Uses

1. KOH is used as an electrolyte in all the alkaline batteries

2. By saponification, KOH is used for making solid as well as liquid soaps.

3. Many of the potassium salts that are used in many industrial purposes are manufactured by reacting KOH.

4. They are also used in chemical manufacturing, fertilizers production, petrochemical refining and cleansing solutions.

It is a chemical compound with the formula C2H3N or CH3CN and it is a volatile organic compound. Acetonitrile is also called Cyanomethane or Methane Carbonitrile. It’s IUPAC name is Acetonitrile. It is a nitrile which is a hydrogen cyanide where the hydrogen (H) is replaced by a methyl group (-CH3). Acetonitrile is a limpid liquid, which is totally colourless. It has an aromatic odor. Compared with water it is less dense than water. When compared with air, it’s vapours are denser. Acetonitrile is easily soluble in water and it has a sweetish taste. It is used as a medium-polarity solvent in the laboratory. Acetonitrile was first prepared by Jean Baptiste Dumas in the year of 1847. It is mainly produced as a byproduct of acrylonitrile manufacture.  In the European Economic Area since March 2000,  acetonitrile has been banned in cosmetic products. It is often preferred as safe for domestic use.

Properties 0f Acetonitrile – C2H3N or CH3CN

1. Molecular weight: 41.05 g/mol

2. Density: 786 kg/m3

3. Melting point: –46oC to –44oC

4. Boiling point: 81.3oC to 82.1oC

5. IUPAC ID: Acetonitrile

6. Colour: Colorless

7. Odor: Aromatic odor

8. Taste: Sweetish taste

9. Solubility: Soluble in water

10. Chemical names: Methyl cyanide, Cyanomethane, Ethanenitrile

Structure Of Acetonitrile – C2H3N or  CH3CN

Acetonitrile is classified as a nitrile in terms of its functional group. As per organic chemistry, a nitrile is defined as a carbon atom that contains a triple bond to a nitrogen atom. Acetonitrile is the simplest organic nitrile which contains a carbon nitrogen triple bond. 

Preparation Of Acetonitrile – C2H3N or  CH3CN

By manufacturing acrylonitrile, it is obtained as a byproduct. It can also be synthesized by hydrogenation of mixtures of carbon monoxide or dehydration of acetamide and ammonia. A method was disclosed with the invention for preparing high purity Acetonitrile from acetic acid and ammonia by two steps which consist of the following two steps, 1. neutralizing acetic acid and ammonia to generate ammonium acetate, 2. Mixing aqueous solution of ammonium acetate and gaseous ammonia, preheating and making the mixture enter a fixed bed reactor which is filled with a catalyst aluminium oxide for reaction to generate acetonitrile which containing mixed gas, after continuously refining the gas we got pure Acetonitrile. 

Uses Of Acetonitrile (C2H3N)

1. In the extraction process of hydrocarbons, acetonitrile is used as a solvent.

2. For the chemical reactions and in chromatography chemists use it as a solvent.

3. To separate fatty acid from vegetable oil we use acetonitrile.

4. Acetonitrile is used in making perfumes.

5. In the production of synthetic pharmaceuticals, acetonitrile is widely used.

6. Acetonitrile is used in the manufacturing of rubber.

7. It is used in extraction of copper as well as refining.

8. In electrochemical cells, it is used as a solvent.

9. Because of its relatively high dielectric constant and ability to dissolve electrolytes, it is widely used in battery application.

10.  Acetonitrile is being used in high-performance liquid chromatography (HPLC).

11.  Acetonitrile has been used in formulations for nail polish remover

12. In the manufacturing of DNA oligonucleotides, in a pharmaceutical field and in photographic film, acetonitrile is used as a solvent.

Fun Facts

1. Acetonitrile is a liquid that is colorless.

2. In the group nitrile acetonitrile is the simplest molecule.

3. Acetonitrile is quite cheap because it is made when plastic is being made.

4. Acetonitrile must be handled with caution because it is an extremely dangerous product, it can cause severe health effects or death.  Since acetonitrile is flammable, it can hurt our eyes.

5. Symptoms of acetonitrile exposure look like cyanide exposure and it can include pink colouring of the skin, dilated pupils, headache, nausea, and vomiting, dizziness, weakness, stiffness of the lower jaw, anxiety, pain and tightness in the chest, rapid breathing and pulse, irregular heartbeat, shortness of breath, etc.

6. Despite its toxicity, it has been used in formulations for nail polish remover. By acetonitrile-based nail polish remover, at least two cases have been reported of accidental poisoning of young children, one of which was fatal.

7. In the European Economic Area since March 2000,  acetonitrile has been banned in cosmetic products. It is often preferred as safe for domestic use.

 

 

Acids, bases and salts affect chemistry as well as our day to day life. They can be easily identified by their taste; that is acids taste sour and bases taste bitter and salts themselves have salty taste.

 

 

Acids are usually found in many substances including various food items but their presence in many fruits is very prominent, for example:

 

 

Apart from these, there are some acids which are widely used in the laboratory, like hydrochloric acid, sulphuric acid and nitric acid.

 

 

Usually bases are found in household cleaners only to clean grease from the windows and the floors and it is also found in soaps, toothpaste, egg whites, dish washing liquids and household ammonia.

 

 

Our body contains some very common acids in the stomach like the dilute hydrochloric acid, which causes food indigestion. When the contents of our stomach become too acidic, we usually get indigestion and a burning sensation in our stomach.

 

 

Acids and bases also regulate some metabolic activities in the human body through the process of equilibrium. Bee stings are acidic in nature while the wasp stings are alkaline in nature. 

 

All acids when reacted with metals generate hydrogen gas. Hydrogen is usually common to all acids.

 

Acid + Metal = Salt + Hydrogen

 

Properties of Acids

            HCl + H2O → H+ + Cl–

 

 

            Zn + 2HCl → ZnCl₂ + H₂

• When acids react with limestone (CaCO₃), it produces carbon dioxide. For example,HCl reacts with limestone to produce carbonic acid and calcium chloride.

            CaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O

• Acids are classified into organic and inorganic acids. The best example of organic acid is acetic acid CH₃COOH, and inorganic acids are those which are produced from minerals; for example, sulphuric acid H₂SO₄, and hydrochloric acid, etc.

 

 

On the Basis of Number of Hydrogen Ion, Acids can be Classified as:

 

1. Monoprotic Acid – They can produce one mole of 

 

[H^{+}] ions per mole of acid, ex – HCL.

 

2. Diprotic Acid – They can produce two moles of 

 

[H^{+}] ions per mole of acid, ex – [H_{2}SO_{4}]

 

3. Triprotic Acid – They produce three moles of 

 

[H^{+}] ions per mole of acid, ex – [H_{3}PO_{4}]

 

On the Basis of Strengths to Donate Hydrogen Ions, Acids can be Classified as:

 

 

Strong Acids: These acids get completely (100%) ionized in the aqueous solutions. Thus, at equilibrium, the concentration of acid molecules becomes very less and concentration of hydrogen ion reaches to the maximum; for example,

 

HCl,HNO3,HClO4

 

Weak Acids: These acids are only partially ionized in solution at equilibrium state. At equilibrium state, molecules of acid are present in a considerable amount and the concentration of hydrogen ion is less, for example,

 

HF,CH3COOH

 

Properties of Bases:

• Bases are compounds that yield hydroxide ion

• (OH−)

• , when it is dissolved in water.

 

 

 

Strength of Bases-

Strong Bases: These are the bases which are completely ionized in water to produce hydroxide ions, e.g., sodium hydroxide

NaOH₈ [leftrightharpoons] Na_(aq)⁺ + OH_(aq)^–

 

Weak Bases: These are the bases which are partially ionized and the equilibrium lies mostly towards the reactants side, e.g., ammonia in water

NH_3(aq) + H₂O_(l) [leftrightharpoons] NH_4(aq)⁺ + OH_(aq)^–

Properties of Salts:

Salts are formed by the combination of acid and base through the neutralization reaction.

 

The acidic and basic nature of salts usually depends on the acid and base from which the salt evolved in a neutralization reaction.

 

 

Example:

NaOH+HCl→NaCl+H2O

 

HCl + NH4OH → NH4Cl + H2

 

CH3COOH + NaOH → CH3COONa + H

 

CH3COOH + NH4OH → CH3COO NH4+ H2O

 

The most well-known or common salt is sodium chloride or table salt which is formed by the combination of a strong base sodium hydroxide and strong acid hydrochloric acid. 

 

HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)

 

Other examples include Epsom salt 

 

(MgSO4)

 

which is used in bath salts, ammonium nitrate

 

(NH4NO3)

 

is used as fertilizer, and baking soda

 

(NaHCO3)

 

is used in cooking.

 

The pH of a solution of salt also depends on the strength of acids and bases which are combined in the neutralization reaction.

 

Addition of Acids or Bases to Water:

The process of dissolving an acid or a base in water is highly exothermic. As this reaction usually generates a lot of heat, so there must be exclusive care taken while mixing the concentrated acids with water, especially when nitric acid or sulphuric acid is mixed with water.

 

 

Rules: The acid must be added slowly to the water with continuous and constant stirring, otherwise it can cause the mixture to splash out which in turn causes burns.

 

 

The glass container may also break due to excessive heating which can cause damage. When an acid or base is mixed with water, it results in dilution. It decreases the concentration of ions per unit volume thereby easily dissipating the effect of heat.

 

 

Uses of Acids 

Below are the uses of different types of acids: 

1. Hydrochloric Acid

• Hydrochloric acid is used in different industries for heating applications. This acid is applied to remove deposits from the inside of the boiler. 

• It is also used to clean silverware and sinks. 

2. Sulphuric Acid 

• Sulphuric acid is used to manufacture paints, dyes, drugs, and fertilizers. 

• It is also used in car batteries. 

3. Nitric Acid 

4. Acetic Acid 

• Acetic acid can be used as a cleaning agent to clean windows, utensils, floors, etc. 

• Acetic acid is an effective ingredient to enhance the flavor of food items. 

• Acetic acid helps in the removal of stains from woodwork and carpets. 

• Acetic acid is used as a preservative in packaged foods such as sauces, ketchup, pickles, etc. 

Uses of Bases 

Here are some uses of different types of bases:

1. Calcium Hydroxide 

• Calcium hydroxide is used to neutralize acidity in the soil. 

• Calcium hydroxide is a vital ingredient in mortar and whitewash 

• It is an essential component of the Bordeaux mixture, which is used to protect agricultural crops from pests.

• Calcium hydroxide is also used to prepare dry mixes for painting. 

2. Sodium Hydroxide 

• Sodium hydroxide is used in the production of detergents, textiles, and paper. 

• Sodium hydroxide is used in households for unblocking drains. 

3. Ammonium Hydroxide 

• Ammonium hydroxide is used as a reagent in laboratories. 

• Ammonium hydroxide is also used to manufacture plastic, dye, rayon, etc. 

Learning about Acids Bases and Salts | Properties of Acids, Bases and Salts

Acids, bases, and salts are an important part of chemistry. By learning the concept of acids, bases, and salts, you can understand how these molecules react with different elements. To start learning this concept, you can refer to ’s website to get a better understanding of acids, bases, and salts. Below are some more tips to help you understand this topic: 

• Read the definitions of acids, bases, and salts thoroughly to understand their meanings. If you know the meaning of all these substances, it will be easier to understand their uses and properties. 

• Go through your textbook and read the detailed explanations of Acids, Bases and Salts to get an idea of what this topic is about. 

• Use different reference books and guides to improve your understanding of acids, bases, and salts. These books provide you with pictorial illustrations to help you understand the concept clearly. 

• Once you are done with the textbooks, you should try to answer the exercise questions given in these books. These questions will help you test your knowledge and give you an idea of the type of questions that can come in your exams. 

• To explore more questions, you should refer to sample papers and previous year question papers of chemistry. These papers will assist you in revisions and exam preparations. 

• Gain more knowledge about acids, bases, and salts from ’s online learning platform. Here, you will find all the study resources you need to study the different concepts of chemistry and enhance your knowledge.

The terms Alcohols Phenols and Ethers belong to the class of organic compounds. These compounds have a huge application count in industries for domestic purposes. When the hydroxyl (-OH) group bonds with the saturated carbon atom, we receive Alcohol. And the dehydration of alcohol forms Ether. Based on the hydroxyl group, there are three types of alcohol named Monohydric, Dihydric, and Trihydric.

These compounds are the organic compound classes that find diverse usage in a wide range of industries and for domestic purposes.

• Alcohol is formed while the saturated carbon atom is bonded to a hydroxyl (-OH) group.

• Phenol is formed when the hydrogen atom present in a benzene molecule gets replaced by the -OH group.

• The ethers are formed when an oxygen atom is connected to either two aryl or alkyl groups.

Let us look at more detail about the types of alcohol, ether, and phenol, including their classification, with a few examples:

Classification of Alcohol

Based on the number of attached hydroxyl groups, alcohol can be classified into three types, as listed below:

• Monohydric alcohols: These contain one -OH group. An example is CH3CH2-OH.

• Dihydric alcohols: These contain two -OH groups. An example is 1,2-Ethanediol.

• Trihydric alcohols: These contain three -OH groups. An example is 1,2,3-Propantriol.

Based on the number of carbon atoms that are attached to the carbon that is bonded directly with the -OH group, alcohols are classified into three types.

• Primary alcohols – Here, one carbon atom is attached directly.

• Secondary alcohols – Here, two carbon atoms are attached directly.

• Tertiary alcohols – Here, three carbon atoms are attached directly.
  

Classification of Phenol

Based on the number of hydroxyl groups count attached, phenols are classified into three types, as listed below:

• Monohydric phenols – These contain one -OH group.

• Dihydric phenols – These contain two -OH groups, maybe “ortho-,” “meta-” or “para-” derivatives.

• Trihydric phenols – These contain three -OH groups.
  

Classification of Ether

Based on the aryl or alkyl groups type attached to the oxygen atom in ether, we can classify it into two types.

• Symmetrical Ether – It is also called the simple ether; the aryl or the alkyl group that is attached to either side of the oxygen atoms are similar. Examples can be given as C₂H₅OC₂H₅, CH₃OCH₃, and more.

• Unsymmetrical Ether – Unsymmetrical ether – We can also refer this to as mixed either, which is the aryl or the alkyl group, attached to either side of the oxygen atoms and are not similar. Examples can be given as C₂H₅OC₆H₅, CH₃OC₂H₅, and more.
  

Nomenclature of Alcohols, Phenols, and Ethers

1. Nomenclature of Alcohols

Alcohols is three major classes which are listed below.

• Monohydric Alcohol

• Dihydric Alcohol

• Trihydric Alcohol

Let us now discuss the nomenclature of these alcohols.

Monohydric alcohols are given with the general formula C_nH_2n+1OH, where n = 1, 2, and so on. Also, we can represent them as R-OH, where R denotes an alkyl group.

Common System

In the common system, we can name monohydric alcohols as Alkyl Alcohol. We can get their names by adding the name alcohol after the alkyl group name is present in the molecule. For example, the CH3-OH compound has one methyl group with an alcohol group. Therefore, we call it Methyl Alcohol.

Dihydric alcohols are given with the general formula, (CH2)n(OH)2, where n= 2,3,4, and so on. Due to their sweet taste, we refer to them as Glycols. Based on the two hydroxyl group’s relative position, we can classify these as α, β, ϒ, ….., ω-glycols, and more. Let us look at their nomenclature system.

Common System

In the common system, we name the α- glycols simply by adding the word Glycol after the end of the alkene name. In contrast, the β, ϒ … ω – glycols get their names the same as the corresponding polyethylene glycols. For example,

The formula of trihydric alcohols can be given as(CH2)n(OH)3 where n = 3, 4, 5, ….., and so on. We do not have any general nomenclature rules in this system. So, there is only the IUPAC rule. In the trihydric alcohol IUPAC system, we call them Alkanethiols and use Arabic numerals to indicate the OH group position.

2. Nomenclature of Phenols

Phenol is the simplest derivative of benzene. It is also the common name and an accepted IUPAC name as well. We can name the substituted phenols as the derivatives of phenols both in IUPAC and the common system.

In this common system, we can indicate the substituent position that is on the benzene ring with respect to the –OH group, by adding the prefix like meta (m-) for 1,3, ortho (o-) for 1:2, and para (p-) for 1,4.

Nomenclature of Ethers

Common System

We can get the common names of ethers simply by naming the two aryl or alkyl groups linked to oxygen atoms as separate words in alphabetical order and adding ether at the end. In the case of symmetrical ethers, we use the “di” prefix before the alkyl or the aryl group name.

 

Tests to distinguish between Phenol, Alcohol, and Ether

To differentiate and identify if the given compound is an alcohol, phenol, or ether, the following tests can be employed:

(i) To differentiate between alcohols and phenols:

 

(ii) To differentiate between phenols and ethers:

 

(iii) To differentiate between Alcohol and ether:

 

In this way, alcohols, phenols, and ethers compounds can be distinguished. There are several other methods too, for example, different physical properties such as density, specific gravity, flashpoints, etc.

 

What is Allylic Carbon?

Allylic carbon definition can be given as a carbon atom bonded to another carbon atom, which in turn is bonded doubly to another carbon atom, in the Modern Periodic table, where all the known elements are arranged in increasing order considering the atomic number. There are 18 vertical columns known as groups and seven horizontal rows, known as periods.

The periodic table’s bottom part contains two series of 14 elements, which are known as an f-block element. The left side of the Modern Periodic Table contains metals mainly, whereas the right side contains the non-metallic region. A few elements show the intermediate properties of metals and non-metals. Such elements are called metalloids and are located in between metals and non-metals in the form of a zig-zag line.

Metals are identified as elements that are highly reactive and electropositive in nature. The non-metals are electronegative in nature, unlike metals. Carbon is one of the most commonly used non-metal. It is a basic of all other organic compounds.

Allylic Carbon Meaning

The double-bonded carbon atoms are further classified as vinylic and allylic carbon atoms. The general chemical formula for the vinyl group is R-CH=CH2, where both the carbon atoms are bonded with a double bond, and R is attached at the vinylic position.

• Since both the carbon atoms form a double covalent bond, so both of them are sp2 hybridized. The allylic position is also similar to a vinylic position. It is bonded to a carbon atom that is bonded doubly to another carbon atom.

• The general formula of allyl is given as – R-CH2-CH=CH2, where the asterisk carbon atom is an allylic carbon atom. Unlike the vinyl group, the allylic carbon atom is sp3 hybridized as it bonded with CH=CH2 via a single covalent bond.

• The allylic carbon imparts unique chemical properties to the allylic group, and the presence of this group in different compounds form allylic compounds, used to prepare various natural products like terpenes, natural rubber, and many more.

Allylic Carbon Atoms

The allylic carbon atoms are sp3 hybridized carbon atoms in the allylic group, RCH2-CH=CH2, that is bonded with the -CH=CH2 group.

For example, in propene, the highlighted atom is the allylic carbon atom (CH3-CH=CH2). Likewise, in cyclohexene, the carbon atoms that are next to the double bond are known as the allylic carbon atoms.

Hydrocarbons

Organic compounds that are composed of different elements with a parent carbon chain are referred to as hydrocarbons. These are the most common organic compounds which are composed of mainly hydrogen and carbon.

• Carbon exhibits the tetravalency. So, it can form four covalent bonds either with the same or different elements.

• Because of its tetravalency, carbon exhibits catenation and can form different organic compounds.

• Catenation is the property of either carbon or other elements that help to form covalent bonds with the same element.

• Based on the carbon atoms bonding count with a carbon atom, we can classify these as primary, secondary, and tertiary carbon atoms.

• A carbon atom that is bonded with one other carbon atom is called a primary carbon atom.

For example, in the ethane molecule (CH3-CH3), both the carbon atoms are bonded with one other carbon atoms. So, both carbon atoms are the primary carbon atom here. The secondary carbon atom is bonded with the other two carbon atoms, and the tertiary carbon atom is bonded to the other three carbon atoms.

Allylic Carbocation

The allylic carbocations are ionic species that carry a positive charge on the carbon atom of the molecule. Usually, they form as an intermediate during various chemical reactions.

The stability of the carbocations is determined by the steric hindrance and +I effect of alkyl groups attached to C+ of the carbocation.

As the +I affects the increases of the positively charged carbon atom of the carbocation, it reduces the positive charge that exists on the carbocation. So, as the number of alkyl groups increases on C+, the stability of carbocation increases accordingly.

Thus, the stability order of carbocation can be represented in the following method.

Tertiary Carbocation > Secondary Carbocation > Primary Carbocation

• If the allylic carbon atom is carried by a positive charge in the allylic group, it forms an allylic carbocation. The allylic carbocation is stable because of the delocalization of electrons on carbon atoms.

• Likewise, in the carbocation of cyclohexene case, the formal charge on allylic carbon is +1, and it stabilizes by resonance with a pi-bond.

• If the allylic carbon atom is associated with one carbon atom carrying a +1 charge, it is referred to as a primary allylic carbocation. Since the formal charge of +1 is on primary carbon atom here, it is named as primary allylic carbocation.

• In the case of the secondary allylic carbocation, the +1 formal charge is distributed on the secondary carbon atom the same as in cyclohexene cation.

• A tertiary allylic carbocation has a +1 charge on a cation’s tertiary carbon atom.

Students may already have been introduced to the compound ammonia, and have some idea about its composition. It is a combination of three hydrogen atoms or molecules and nitrogen. The combination leads to the formation of ammonia gas. Besides this, an understanding of the properties of ammonia is also important. 

We will not go into a relatively elaborate discussion on ammonia but also focus on its important attributes. By the end of this discussion, you will also have an idea about the laboratory preparation of ammonia acid. Do note, this is a vital chapter in your curriculum.

Nature of Ammonia

Now, we will discuss the nature and other properties of ammonia in the upcoming paragraph. Ammonia is also called nitrogen trihydride or azane. NH₃ is the chemical formula for ammonia. The NH₃ molecule has a trigonal pyramidal shape. The hybridisation of this molecule is sp³. Nitrogen is the base of ammonia which here makes a single electron pair. It can also form a homogeneous mixture with water. It is a polar molecule. If we compare it with NF₃, in spite of the fact that fluorine is the most electronegative element, the resultant dipole of NH₃ is greater than NH₃. The reason is, that in NH₃ the orbital dipole of hydrogen is in the same direction as nitrogen.

On the other hand, the orbital dipole of fluorine is in the opposite direction with nitrogen. It also plays a very important role in the human body system. The kidneys secrete ammonia, which helps in the neutralization of acids within the body. It also occurs naturally in our environment, some in volcanic areas and some in rainwater.

Structure of Ammonia

The molecules of ammonia exhibit a pyramidal shape and the nitrogen atom is placed at the vertex. Ammonia molecules constantly undergo inversion motion wherein the nitrogen atom moves through the plane of a hydrogen atom-like an upside-down umbrella.

The properties of ammonia that are seen are owing to ammonia acting as a base. The atom of nitrogen may either bond to a metal cation or to a proton such as forming an ammonium ion.  

When the ammonia is frozen or in liquid form, there exists molecular attraction through the shared hydrogen atom between two molecules. Such sharing is called hydrogen bonding. Due to this bond, an association takes place leading to the formation of compounds that contain free electrons that may be obtained by treating ammonia solutions with various complexing agents.

Properties of Ammonia 

The physical properties of ammonia are listed below in detail–

• Colorless gas having a pungent and suffocating odor.

• Freezing point is -77.7°C.

• Boiling point is -33.35°C.

• Lighter than air given its density to be 0.583 times of air. 

• Molar mass is 17.03g/mol.

Given the extremely low boiling point of ammonia, liquid ammonia can be readily stored at high pressure and low temperature. In its purest form, anhydrous ammonia can readily absorb moisture (hygroscopic). It also retains alkaline properties and amounts to being corrosive. 

Do You Know?

Research studies have found out that ammonia can have a toxic effect on the glial and nerve cells of the brain. While in healthy people, ammonia is converted into urea in the liver which is eventually washed out with urine, there could be excessive concentration of ammonia in blood for people with impaired liver function. The higher levels lead to ammonia toxicity triggering seizures and coma. 

Laboratory Preparation of Ammonia 

Ammonia is prepared by the Haber-Bosch process. The process, in principle, combines nitrogen from the air with that of hydrogen that is mainly derived from natural gas such as methane. It leads to the production of ammonia. The production of ammonia is exothermic, and this reaction is reversible in nature.

In the presence of a metal catalyst, elemental hydrogen and elemental nitrogen are reacted which gives out ammonia gas. The reaction is conducted at very high pressure as well as high temperature (400-550°C). 

Uses of Ammonia 

• Ammonia acts as a precursor to different nitrogen compounds like amino acids, urea, phenol, hydrogen cyanide, acrylonitrile, nitric acid, soda ash, among others.

• It finds extensive usage in the production of polymers, fertilizers, synthetic fibers such as rayon and nylon, cleaning agents, refrigerants along with explosives like nitroglycerin and TNT. 

Even though ammonia is present and finds usage in many household products and purposes; its inhalation can be highly toxic. The fumes of ammonia have a very sharp and pungent odor that can cause irritation in nose, eye, mucous membranes and skin. It can also cause severe damage to the respiratory tract. When exposed to a very high concentration of ammonia gas, it may lead to permanent lung damage or even death. 

What is Nitric Acid?

Nitric acid is a strong acid with a pH level of 1.2 and is also called aqua fortis and the spirit of nitre. The chemical formula for nitric acid is HNO₃. Nitric acid is formed by the reaction Of water and nitrogen dioxide. The reaction is as follows-

3NO₂ + H₂O → HNO₃ + NO. It reacts with metals, hydroxides and oxides to form salts.

Properties of Nitric Acid 

• Nitric acid is a fuming, colorless and highly corrosive agent.

• Freezing point is -42°C.

• Boiling point is 83°C.

• PH is approximately 3.01.

• Nitrogen atom is bonded to a hydroxyl group and forms equivalent bonds with the rest oxygen atoms.

• It is a conjugate acid of a nitrate.

Test Yourself 

1. The Factories Producing Fertilizers Need to have Plant(s) of-

1.  ammonium nitrate production.

2.  nitric acid production.

3. ammonia production.

4.  all of the above.

2. During Ammonia Production, Low Temperature is Maintained. The Benefit of Low Temperature –

1.  better yields only.

2.  better quality.

3.  slow and better yields. 

4.  better quality.

3.     _______________ can be Used to Catalyze the Synthesis of Ammonia.

1.  Iron

2.  Nickel 

3.  Platinum 

4.  Aluminum 

Solutions: 1. (d) all of the above 

                    2. (c) slow and better yields 

                    3. (a) Iron

Laboratory Preparation of Nitric Acid 

Laboratory preparation of Nitric Acid (HNO3) involves heating of nitrate salt with that of concentrated sulphuric acid.

Nitric acid vapor is condensed into brown-coloured liquid within a receiver that is cooled by cold water. The oxides of nitrogen that remain dissolved in the mixture are removed by way of re-distillation.  

Uses of Nitric Acid 

• Nitric acid has several industrial uses and acts as a building block chemical for many other chemical compounds. It is used for the manufacture of different polymers such as polyurethane and polyamide. 

• It is used to make explosives such as nitro-glycerine and trinitrotoluene (T.N.T). Nitric acid also finds usage in the aerospace industry as rocket propellant.

• Nitric acid is used in fertilizer production such as ammonium nitrate, calcium nitrate etc. It is also used in our daily lives as laboratory reagents, for cleaning food and dairy equipment, among others. 

Chemistry can prove to be one of the difficult subjects that you may have to prepare in your syllabus. However, you can join our online classes where even the basics of the subject will be explained along with providing clarification of all your doubts on ammonia and nitric acid formulae properties preparation. 

Various topics, such as properties of ammonia, are frequently touched upon in examination. Hence, when you have a clear understanding of such topics, you can hit the ground running in terms of preparation.