Category: Chemistry Notes PPT

The atomic number and symbols are important in chemistry. The element symbol is a one- or two-letter abbreviation of the name of the element. While writing long chemical equations, we need to write a short form of the compounds and elements that time these symbols are very useful. The atomic number of elements gives an idea about the atomic structure of elements, such as how many electrons and protons that particular element has. The first 20 elements of the periodic table are given in the figure below.

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What are the First 20 Elements of the Periodic Table?

The first 20 elements of the periodic table, which have atomic numbers 1-20, are listed below.

Each element consists of distinct properties owing to its atomic number, atomic mass, electronic configuration, electronegativity, electron gain enthalpy, etc.

Importance of The Atomic Number of An Element in A Periodic Table

Before knowing the importance of an atomic number of elements take a look at the following definitions.

• Atomic number – The atomic number tells us how many protons are there in the nucleus.

• Protons – It is a subatomic (occurring within an atom) particle. It has a positive charge. It resides in the nucleus of an atom of the element.

• Neutrons – It is also a subatomic particle. Neutrons have a neutral charge. A neutron weighs a little bit higher than a proton. Neutrons, along with the protons, add up to form the nucleus of the atom.

• Electrons – Electrons are also subatomic. Electrons tend to orbit around the nucleus. The electrons are negatively charged. The size of the electrons is smaller than that of the nucleus. Electrons have an equal charge as the proton, but with a negative sign. The mass of an electron is almost 1/1836 times the mass of a proton.

The atomic number of an element in the periodic table provides us with the following information:

• Gives an idea about the number of protons in the nucleus of an atom

• The number of electrons surrounding the nucleus in a neutral atom.

• In other words, we can say that the atomic number is equal to the charge on the nucleus. Hence, it is also similar to the number of protons in the nucleus. It is numerically equal to the number of electrons in a neutral atom.

• Let’s try to understand it further with the example of Oxygen. Oxygen has an atomic number of 8. This implies that in the neutral state, the number of protons in the nucleus is 8. The number of electrons is 8. Similarly, in sodium, which has an atomic number of 11, the sodium atom’s nucleus consists of 11 protons. It has 11 electrons surrounding the nucleus. As we know that the atomic number is equal to the number of electrons, we can easily predict the atom’s electronic configuration by merely knowing its atomic number.

How are the first 20 elements of the periodic table useful for us?

Some of the elements of the first 20 elements of the periodic table are very much helpful for our daily life such as: 

• Oxygen (O)- Oxygen has an essential role in respiration. Respiration is the energy-producing mechanism that dictates the metabolisms of most living organisms. Humans, along with many other beings, require oxygen for breathing. Oxygen is generated during the process of photosynthesis in plants and different types of microorganisms.

• Carbon (C)- Carbon consists of 18% of the human body. Protein, sugar and other essential compounds including glucose contain carbon. Fossil fuels, like petroleum, CNG etc. also contain carbon.

• Aluminium (Al)- Aluminium, being malleable and soft, is used in the making of various products like utensils, aeroplane parts, window frames etc. 

• Silicon (Si) – Silicon, a semiconductor, is used in computer chips.

• Phosphorus (P)- Phosphorus is used in the military to make weapons (white phosphorus). Phosphorus is an integral part of ATP, the energy currency of our body.

• Calcium (Ca)- Calcium helps in maintaining bone strength.

Noble Gases in the First 20 Elements of the Periodic Table

First, we need to know what noble gases are, Noble gases are also called inert gases. Noble gases are situated in the 18th group of the periodic table. These are known to be the least reactive or extremely non-reactive. The noble gases were characterized later than other elements.

So, in the first 20 elements, there are three noble gases, namely, Helium (He), Neon (Ne), and Argon (Ar). Helium has an atomic number 2, Neon has an atomic number of 10, while Argon has an atomic number of 18.

Conclusion

Hence knowing about the first twenty elements of the periodic table is the basic step in order to gain knowledge about all the elements. This article will develop an understanding of atomic numbers and symbols of elements.

What Are Fossil Fuels?

The earth is undergoing a variety of processes all the time. These processes are so slow that it takes millions of years to see their effect. Over a period of time, the layer of soil on the surface of the earth gets covered with newer layers, which keep getting deposited on top of the previous one. It happens that the remains of dead and decayed plants and organisms get trapped between these layers. When sediments are compressed together, it can lead to the formation of sedimentary rocks. These stratified rocks are soft and are often found to bear the impressions of dead plants and animals that get trapped in between them. These impressions are called fossils. 

Fossil fuels are called so because they are formed when the dead remains of living organisms get trapped between the layers of soil, and overtime get subjected to heat and pressure for a span of millions of years to form fuels. Fossil fuels are exhaustible, non-renewable, finite sources of energy. Using them in an injudicious manner can lead to their exhaustion. Formation of these fuels constitutes a part of the carbon cycle in nature. 

How is Coal Formed?

Millions of years ago, the earth was covered with lush, green vegetation. As these forests died, the soil bed was layered with plant remains. The debris got covered with another layer of soil, and the process continued. The buried vegetation got compressed under the effect of intense heat and pressure. The time period during which the formation of coal took place from the decaying vegetation is called the carboniferous age, and the process is called carbonization. 

Coal Formation Stages

The formation of coal is a four-stage process, depending on the conditions to which the plant debris was subjected. More the heat and pressure to which vegetation is subjected, better is the quality of coal. Superior quality coal is denser, has more carbon content, contains lesser moisture and has a better calorific value. The various stages of coal formation are described below:

1. Peat- Stage One

The formation of peat is the first stage in the formation of coal. It is a partially decomposed vegetable matter with very low carbon content. This incomplete decomposition leads to the formation of a slightly brown, organic mass called peat. It is fibrous and spongy, has high moisture content and is rarely used as a source of heat.

2. Lignite- Stage Two 

This is the second stage in which peat is subjected to more heat and pressure due to the weight of sediments getting accumulated above. It is darker in colour than peat, but the plant traces can still be spotted. 

3. Bituminous- Stage Three

When the pressure increases further, lignite becomes denser and more compact. At this stage, no traces of vegetation can be spotted. The carbon content increases and the moisture content decreases. Bituminous coal is the most widely used and easily available variety of coal used for domestic and industrial purposes. 

4. Anthracite- Stage Four 

It is the hardest and densest variety of coal. Since, the moisture is almost not there, anthracite burns with a short flame and produces little smoke. It has the maximum carbon content, and its calorific value is higher than the other varieties, making it the most superior quality of coal. 

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Uses of Coal

1. Coal has conventionally been used as a household and industrial fuel. Throughout the Industrial Revolution, coal was used as a source of energy.

2. Coal is used in thermal power plants to produce electricity. 

3. It is used for heating purposes.

How Is Petroleum Formed?

Petroleum is a thick, viscous, black liquid. Because of its value in today’s world, it is also called black gold. The formation of petroleum takes millions of years. It is formed when the dead remains of animals below the surface of the earth. As these dead remains are subjected to heat and pressure, they get decomposed and liquefied. This liquid form of organic matter is the petroleum or crude oil. It can be obtained by digging oil wells and refining the oil to yield several products or fractions. The dying aquatic animals get submerged, and get decomposed on the sea bed. They also form petroleum under similar conditions. 

Uses Of Petroleum

1. It is used to obtain a variety of reactions such as petrol, naphtha, paraffin wax, diesel etc. 

2. Its products are used as fuels in automobiles and industries. 

3. It is used in the manufacture of plastics and synthetic fibres and polymers.

Any substance that when undergoing chemical or nuclear change to produce energy and which can be converted into useful work is known as fuel.

The calorific value of a fuel is defined as the amount of energy released when the unit mass of the substance(fuel) undergoes complete combustion. 

The SI Unit to Measure Calorific Value is J/kg.

Fuels can be Generally Classified Into

Renewable Sources of Energy

The sources of energy that when once consumed can be obtained back by various biogeochemical cycles occurring in nature are known as renewable sources of energy. Energy from running water is an example of a renewable source of energy because once consumed we can get it back through rain. Another example is solar energy. For sustainable development, we should try to make maximum use of renewable energy resources. 

Non-Renewable Sources of Energy

The sources of energy that once consumed cannot be obtained back by any biogeochemical cycle is known as a non-renewable energy resource. For example, fossil fuels take millions of years to come into existence, once finished cannot be generated back for our use, hence termed non-renewable energy resources. Non-renewable resources must be used judiciously, before their use all other alternative sources of energy must be taken into consideration.

 

Some Properties of Ideal Fuel are

1. Ignition Temperature: The temperature at which a substance catches fire is known as its ignition temperature. An ideal fuel must have an easily attainable ignition temperature. For example, the chemical present on the head of the matchstick catches fire easily using the heat produced by friction generated by rubbing it with the side of the matchbox. 

2. Calorific Value: The purpose of the fuel is to convert its chemical energy into heat and other forms of energy on burning. An ideal fuel must have a high calorific value to serve the purpose better.

3. Impact on Environment: An ideal fuel must leave less residue (harmful) on burning. It should undergo complete combustion so as not to add particulate matter to the atmosphere. For example, Compressed natural gas leaves almost no residue on burning. 

4. Rate of Combustion: An ideal fuel must burn at a constant/moderate rate. Rapid and explosive combustion is not the characteristic feature of an ideal fuel. 

5. Availability: An ideal fuel should be easily and ever available. It should be available at a low cost. 

6. Handling: Easy storage and transportation prevent the loss of fuel and also protects the environment. It improves the accessibility of the fuel.

Types of Fuels 

1. On Basis of Their State

1. Solid Fuels: The fuels which exist in a solid state only in their primary stage are termed solid fuels.

2. Liquid Fuels: The fuels which exist in a liquid state only in their primary stage are termed liquid fuels.

3. Fuel Gases: The fuels which exist in a gaseous state only in their primary stage are termed fuel gases.

2. On Basis of their Occurrence

1. Natural Fuels: The fuels which are present naturally are known as natural fuels.

2. BioFuels: The fuels obtained from the living matter on earth are termed biofuels.

3. Fossil Fuels: Dead and decaying plants and animals buried deep under the earth, under high pressure and temperature gets converted into extremely high-quality fuel termed fossil fuels. Coal and petroleum are two important types of fossil fuels. Coal is mainly obtained from dead and decaying plants, whereas petroleum (crude oil) is obtained from dead and decaying animals (especially aquatic animals). Since fossil fuels are generated from organic matter, they are a rich source of energy but are non-renewable as it takes millions of years for the conversion of organic matter into fossil fuels.

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4. Artificial Fuels: The fuels which are obtained through different chemical processes are termed artificial fuels. For example, water gas and producer gas are fuels obtained in a laboratory under required conditions.

 

Examples of Fuels

Solid Fuels:

Liquid Fuels:

Gaseous Fuels

Types of Gaseous Fuels

1. Naturally Occurring Gaseous Fuels: Natural gas is found over petroleum deposits and around coal deposits (Firedamp). The composition of natural gas obtained from different sources vary with the main component being methane gas. Other than methane some higher hydrocarbons are also found in natural gas. Traces of H2S gas are also present in Natural gas.

Characteristics- 

1. High calorific value

2. Proper ignition temperature

3. Extraction of natural gas from Petroleum deposits is comparatively easier than extracting from coal deposits.

4. Natural gas can be easily liquified for distribution by tanker. It is termed liquified natural gas (LNG)

2. Gaseous Fuels Derived From Solid Fuels: Methane gas found around coal deposits, Gaseous fuels obtained from waste and biomass, Fuels obtained from industrial processes such as gases produced in blast furnaces. 

3. Gaseous Fuels Obtained From Petroleum: Liquified petroleum gas, Gases obtained from various refining processes, Gaseous fuel obtained from oil gasification. 

4. Gaseous Fuels Obtained From Fermentation Processes: For example, ethyl alcohol is obtained from the fermentation of sugarcane. 

Nuclear Fuels

The energy obtained during nuclear reactions (Nuclear fusion or nuclear fission reactions) is known as nuclear energy and the reactants are termed nuclear fuels. Uranium-235 is a widely used nuclear fuel because – energy released from a single pellet of uranium = energy released from one ton of coal = energy released from 149 gallons of oil = energy released from 17000 cu ft of Natural gas

Apart from Uranium-235, plutonium-239 is also used extensively in nuclear reactions.

Advantages of Nuclear Energy 

1. Sustainable Development: The world population living without electricity is more than one billion. Nuclear energy is the low-cost and ever-available source of energy for developing nations. It is an affordable source of energy. 

2. Climate: Almost all sources of energy emit some or other kind of harmful gases, but nuclear fuel is emissions-free. Nuclear energy prevents more than 52b million metric tons of CO2 from entering our atmosphere. 

3. National Security: Nuclear fuel empowers nations by building weapons for their own security purposes.

Disadvantages of Nuclear Energy

1. High Upfront Costs: Nuclear thermal plants that are needed to harness the nuclear energy of a substance are though cheaper to run, but require an enormous amount of money to establish. 

2. Radioactive Waste: The use of nuclear energy produces Radioactive Waste, which can be dangerous to the environment. And it is also very troublesome to get rid of this waste.

Chromatography is a method for separating a mixture in the laboratory. The mixture is dissolved in a mobile phase fluid (gas, solvent, water, etc.) that transports it through a structure (column, capillary tube, plate, or sheet) on which a stationary phase material is fixed. The stationary process has different affinities for each of the mixture’s constituents. Depending on their interactions with the stationary phase’s surface sites, various molecules remain in the stationary phase for longer or shorter periods of time. As a result, they differentiate since they move at various apparent velocities in the mobile fluid.

This article will study Molecular exclusion chromatography, gel exclusion chromatography, and application of gel chromatography in detail.

Molecular Exclusion Chromatography/ Exclusion Chromatography

Size exclusion chromatography SEC, also known as molecular sieve chromatography, is a chromatographic process that separates molecules in solution based on their size and, in some cases, molecular weight.  Large molecules or macromolecular complexes, such as proteins and industrial polymers, are commonly used. Gel-filtration chromatography is used where an aqueous solution is used to move the sample through the column, as opposed to gel permeation chromatography, which is used when an organic solvent is used as a mobile phase.

Gel Exclusion Chromatography

Gel permeation chromatography (GPC) is a form of size exclusion chromatography (SEC) that uses organic solvents to separate analytes based on their size. Polymer analysis is a popular application of this technique. SEC was first developed as a technique by Lathe and Ruthven in 1955. The term gel permeation chromatography was coined by J.C. Moore of the Dow Chemical Company, who researched the technique in 1964 and licensed the patented column technology to Waters Corporation, which commercialized it in 1964.

Principle of Gel Exclusion Chromatography

• The analytes are separated by GPC based on their size or hydrodynamic volume (radius of gyration). Other separation methods, on the other hand, rely on chemical or physical interactions to distinguish analytes. Porous beads packed in a column are used to separate the particles.

• Since smaller analytes can penetrate pores more quickly, they spend more time in them and hence have a longer retention time. Since these smaller molecules spend more time in the column, they elute later. Larger analytes, on the other hand, spend little or no time in the pores and are easily eluted. A number of molecular weights can be divided in each column.

• Analytes that are too large will not be retained; on the other hand, analytes that are too small will be entirely retained. Analytes that are not retained are eluted with the free volume outside of the particles (Vo), while those that are completely retained are eluted with the volume of solvent held in the pores. The following equation can be used to calculate the total volume, where Vg is the volume of the polymer gel and Vt is the total volume:

Vt = Vg + Vi + Vo

Methods of Gel Filtration Chromatography

1. Almost all gel permeation chromatography is done in chromatography columns. The experimental model is very similar to that of other liquid chromatography techniques. Samples are dissolved in a suitable solvent, which in the case of GPC is usually organic, and then filtered before being injected onto a column. The column is where a multi-component mixture is separated. The use of a pump ensures a steady supply of fresh eluent to the column. A detector is needed because most analytes are not visible to the naked eye. To obtain additional information about the polymer sample, several detectors are often used.

2. The stationary process for GPC is gel. In order to apply a gel to a specific separation, the pore size of the gel must be carefully monitored. The absence of ionizing groups and low affinity for the substances to be separated in a given solvent are also desirable properties of the gel-forming agent.

3. Microporous packing material is used to fill the GPC column. The gel is poured into the column known as the gel filtration column.

4. The eluent (mobile phase) should be a good solvent for the polymer, allowing the polymer to have a high detector response and wetting the packing surface. Tetrahydrofuran is the most common element in GPC polymers that dissolve at room temperature (THF).

5. Piston or peristaltic pumps are the two types of pumps available for uniform distribution of relatively small liquid volumes for GPC.

6. In GPC, a detector will continuously monitor the polymer concentration by weight in the eluting solvent. There are several different types of detectors, which can be classified into two groups. UV absorption, differential refractometer (DRI) or refractive index (RI) detectors, infrared (IR) absorption, and density detectors are the first types of concentration-sensitive detectors.

Application of Gel Filtration Chromatography

GPC is often used to determine the relative molecular weight of polymer samples as well as molecular weight distribution. The molecular volume and shape function, as determined by the intrinsic viscosity, are what GPC truly measures. This relative data can be used to calculate molecular weights within 5% precision if comparable criteria are used. To calibrate the GPC, polystyrene standards with disparities of less than 1.2 are commonly used.

Disadvantages of Gel Permeation chromatography

GPC, on the other hand, has several drawbacks. First, the number of peaks that can be resolved within the short time frame of a GPC run is small. Furthermore, for a satisfactory resolution of peaks, GPC as a technique needs at least a 10% difference in molecular weight. When it comes to polymers, the molecular masses of most of the chains are too close together for the GPC separation to produce anything other than large peaks. Another downside of GPC for polymers is that it needs filtration prior to use to prevent dust and other particulates from destroying the columns and interfering with the detectors.

Did You Know?

SEC is a low-resolution chromatography since it has a hard time distinguishing between similar organisms, so it’s usually used as the last step in purification. Since it can be carried out in native solution conditions while maintaining macromolecular interactions, the technique can be used to determine the quaternary structure of purified proteins with slow exchange times. Since SEC tests the hydrodynamic volume (not the molecular weight), it can detect protein tertiary structure, allowing folded and unfolded forms of the same protein to be distinguished.

SEC may be used to determine the size and polydispersity of a synthesized polymer, or the ability to determine the size distribution of polymer molecules. If known-size standards have been run previously, a calibration curve can be developed to determine the sizes of polymer molecules of interest in the solvent of choice (often THF). Techniques like light scattering and/or viscometry can be used online with SEC to produce absolute molecular weights that don’t require calibration with known molecular weight standards.

Chemistry is often referred to as one central science because it combines together physics, mathematics, biology, and medical line, and the earth and environmental sciences revolving around us. Knowledge of the nature of chemicals and chemical processes that stands as the major reason for us to live on this earth, therefore, provides insights into a variety of physical and biological phenomena and makes lives easier. 

First, try to read, learn and understand the underlying basic concept of the chemistry syllabus and then write down good notes with equations and important concepts which will help you revise them before exams. Break down complex tasks into smaller ones and try to research the in-depth reason for any chemical process involved. Spend a good amount of your time in the chemistry labs for you to learn the concepts with the proof before your eyes. This will make you remember the concepts as a visual effect during your exams. 

Chemistry is a branch of science that is concerned with any smaller or unique substances of which a particular matter is composed and deals in-depth with the investigation and study of their properties and every reaction, and the use of such reactions to form new substances.

One can find traces of chemistry in daily life. The food we eat gives us some form of chemical reactions with the acid that is naturally produced in our stomach that helps in our digestion. The air we breathe has chemical components involved to change and breathe only oxygen for life. The cleaning chemicals used in homes or any places have some percentage of chemicals in them. Our emotions are connected with chemistry as well, oxytocin produced when we are with our loved ones is a form of a chemical reaction and literally every object we can see or touch. Some common chemistry may be obvious, but others might surprise us in unexpected forms. Our body is also made up of many unique chemical compounds, which are combinations of various elements.

Occurrence

When gold is obtained in its pure form, it is seen as a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal.

Chemical Symbol and Isotopes

Gold is a chemical element with the symbol Au derived basically from the Latin term aurum and atomic number 79, making it one of the higher atomic number elements that occur naturally.

Properties and Uses

Gold is one of the densest metals found of all other elements. It is a good conductor of heat and electricity. It is also soft and the most malleable and ductile of all the other elements and hence an ounce (28 grams) can be beaten out to 187 square feet (about 17 square meters) in extremely thin sheets called gold leaf.

More About Gold

Gold is a precious metallic element with atomic number 79 and is a part of the periodic table. Gold falls under the sixth period and group eleven in the periodic table. Gold is a transition metal. The IUPAC defines a transition metal as an element that has a partly filled subshell, or an atom that may give rise to cations despite having an incomplete subshell. 

Occurrence

Gold is a naturally occurring element. It is widespread in all igneous rocks, at low concentrations. It is estimated that its abundance in Earth’s crust is about 0.005 part per million. It occurs mainly in the natural state. It is usually chemically pure, except with tellurium, selenium, and bismuth. The only isotope that occurs naturally for this element is Au-197.

Gold also appears in association with deposits of copper and lead, and while the quantity present is sometimes exceedingly small, it is readily extracted as a by-product in the processing of these base metals. It is highly unusual to see large masses of gold-bearing rock rich enough to be called ores.

Two types of deposits contain a substantial amount of gold. First, the hydrothermal veins, where gold is associated with quartz and pyrite (fool’s gold) and second, the deposits, which are mainly derived from the weathering of gold-bearing rocks 

Chemical Symbol of Gold

The chemical symbol of gold is Au. This symbol is taken from the first two letters of the Latin name of gold: Aurum. 

Gold Atomic Number

The atomic number basically determines the number of protons in the particular element. An element is identified by the number of protons, which is given by the atomic number. 

The atomic number of the element Gold is 79. 

Gold Electron Configuration

An atom has various shells on which electrons revolve around the nucleus. The number of electrons present in each of the shells is known as the electronic configuration of an element.

The electronic configuration of Gold is Xe 4f¹⁴5d¹⁰6s¹.  In a simpler form, the electrons per shell of the Gold atom can be written as 2,8,18,32,18,1. Gold can have a valency between (-1) and +5, the most common being +1 and +3.

Atomic Mass of Gold

The atomic mass of an element refers to the mass of one atom of that element, which is measured in atomic mass units (u), where one atomic mass unit is equivalent to 1/12 the mass of carbon-12 isotope. When calculating the atomic mass of a particular element, we add up the mass of the protons and neutrons, because the mass of the electrons is negligible compared to their mass. 

The average atomic mass for Einsteinium is 196.97. It varies depending on the isotope.  

Isotopes of Gold

Isotopes are forms of an element with the same atomic numbers but different mass numbers, i.e. a different number of neutrons. Gold (Au79) has a single stable isotope, Au-197, and 36 radioisotopes, with Au-195 being the most stable with a half-life of 186 days. Gold is now known to be the heaviest mono-isotopic metal element. 

 

Properties of Gold

Physical Properties of Gold

• Gold is an amazing thermal and electrical conductor. 

• The element is highly resistant to corrosion and is exceptionally durable. It is not harmed by air and most of the reagents

• Gold is lustrous. It is also malleable and ductile. 

• Gold in its purest form is extremely soft. In order to bestow strength to it, it is alloyed with another metal.

• Gold appears in a slightly reddish yellow colour when available in bulk. But when finely separated, it becomes black, violet, or ruby.

Chemical Properties of Gold

• The most common gold compounds are chloro-auric acid and auric chloride.

• Gold is insoluble in most acids but can be dissolved in Aqua Regia (Royal Water). Aqua Regia is a mixture of hydrochloric acid and nitric acid, in which gold forms a tetrachlorocuprate anion. It also dissolves in alkaline solutions cyanide. 

• Gold is one of the least reactive metals, according to the reactivity series of metals. It comes just before platinum, the most non-reactive metal.  

Uses of Gold

• Gold is mainly used for the manufacture of jewelry, glass, and various parts in electronics. Around 75% of the world’s jewelry is made using gold. 

• Gold may be rendered into a thread and used for embroidery. 

• A thin film of this metal is placed on the windows of a large building to simulate the heat of the light. 

• Gold is also used in medicinal products. Its radioactive isotope Au-198 is used to treat tumors in the body.

• A thin layer of gold is applied to astronaut helmets to protect them from UV radiation.

The Haber Bosch process, which is also called the Haber process, is basically one of the most successful and efficient industrial procedures for ammonia production’>production. In the 20th century, a German chemist named Fritz Haber and his assistant developed the Haber process catalyst and high-pressure devices to carry out this process in a laboratory. Later, in 1910, Carl Bosch took the design and created a machine for the industrial-scale production of ammonia. Indeed, this was an essential development in the field of science.

Let us understand the process in detail.

Process and Conditions Explanation

The Haber Bosch process provides a good case study to demonstrate how the industrial chemists use their knowledge of the chemical equilibria affecting factors to find the best conditions that are required to produce a considerable yield of products at a fair rate.

In this process, “the N₂ (atmospheric nitrogen) is converted to NH₃ (ammonia) by reacting with H₂ (hydrogen).”. In this process, a metal catalyst is used, and high pressures and temperatures are maintained.

The raw materials that are used for the process are listed below.

• Air, which supplies the nitrogen.

• Natural gas and water supply the hydrogen and the energy needed to heat the reactants.

• Iron is the catalyst and does not get used up in the reaction.

Let us have a look at the diagram given below.

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• According to the diagram, in the Haber Bosch process, we obtain the nitrogen gas from the air and it combines with the hydrogen atom obtained from natural gas in a 1:3 ratio by volume.

• These gases are passed via 4 beds of catalyst, where the cooling takes place in each pass. This is performed to maintain the equilibrium constant.

• Different conversion levels take place in each pass where unreacted gases are recycled.

• Generally, iron is used as a catalyst in this process, and the complete procedure is conducted by maintaining a pressure of 150 – 200 atm and a temperature ranging from 400 – 450⁰C.

• This process also involves steps such as carbon dioxide removal, shift conversion, methanation, and steam reforming.

• Then, in the final stage of this process, the ammonia gas is cooled down to form a liquid solution. Then it is collected and stored in the containers.

Reaction Rate and Equilibrium

The Haber process for ammonia synthesis is based on the reaction of hydrogen and nitrogen. The chemical reaction can be represented below. It is an exothermic reaction, where energy is released. The Haber process equation is given below.

[N_2(g) + 3H-2(g) rightarrow  2NH_3(g)]

In this reaction, nitrogen is obtained by separating it from the air via liquefaction, and hydrogen is obtained from the natural gas by reforming or steam.

[CH_4(g) + H_2O rightarrow  H_2(g) + CO(g)]

As per the principle of Le Chateleir, ammonia production is favoured by low temperature and high pressure. Typically, the Haber process is carried out at pressures ranging from 200-400 atmospheres and a temperature of 500⁰C. In commercial ammonia production, NH₃ is continuously collected as it is produced. The product removal causes more hydrogen and nitrogen to combine as per Le Chatelier’s principle.

However, this is a reversible reaction, which is affected by changes in pressure, temperature, and catalyst used, mainly in the equilibrium mixture composition, and the reaction rate.

Catalyst Used in Haber Process

Iron can be used as a catalyst, but the catalyst used in the production is not pure iron. It contains potassium hydroxide as a promoter, added to it to increase its efficiency. Usually, this process takes place under high temperature and pressure.

Since the operating temperature is very low, the reaction rate can be increased by using the catalyst, which consists of finely divided the iron-containing molybdenum either as iron oxide or as a promoter.

A few key points are listed below.

• We can also use CaO, K₂O, Al₂O₃, and SiO₂ as promoters of iron instead of using potassium hydroxide.

• Almost, uranium was easier and effective to obtain than osmium.

• The original Haber process reaction chambers used osmium as the catalyst, but it was available in extremely small quantities.

• After extensive research, a much less expensive iron-based catalyst was discovered.

Uses of Ammonia

Ammonia is useful in many areas. A few uses of ammonia are as follows.

Ammonia can be used in making nitro-based explosives, like RDX, TNT, etc.

Ammonia is one of the main components in making fertilizers.

It can also be used in air-conditioning units in buildings, and large-scale refrigeration plants.

It can be used in manufacturing particular drugs such as antimalarials, sulfonamide, and also vitamins, including nicotinamide and thiamine.

Ammonia can also be used in different cleaning products and acts as an effective cleaning agent.

Did you know?

Why is Iron Used as a Catalyst in the Haber Process?

Iron can be used in the Haber process as a low-cost catalyst. Also, it allows an acceptable time to reach a reasonable yield.

How to Get Hydrogen for the Haber Process?

Methane formed from natural gas is the major source of hydrogen. In high pressure and temperature, the pipe inside a reformer has a nickel catalyst. The steam reforming process is carried out by separating the hydrogen and carbon atoms in the natural gas.