Category: Chemistry Notes PPT

Smelting is a process in which the base metal is extracted from the ore by applying heat to it. It is one kind of extractive metallurgy. It is used for the extraction of many metals like copper, aluminium, iron, silver, lead and many other base metals from their respective ores. For the decomposition of the ores, smelting uses heat and chemical reducing agents that eliminate other elements in the form of gases or slag that leaves behind the metal base. 

The reducing agents for smelting are commonly the fossil fuels of carbon such as coke or charcoal that were used in earlier times. Due to the low potential energy of the bonds in carbon dioxide during high temperatures, the oxygen in the ore binds to carbon. Iron smelting is usually carried out in a blast furnace to produce pig iron, which is then converted into Steel.

Carbon is applied as a chemical reactant in order to remove oxygen from the ore that earrings the purified metal element as a product. The source of carbon is oxidised in two different stages. In the first stage, carbon monoxide is produced when the carbon is combusted with oxygen in the air. After many successive interactions of carbon monoxide with oxygen, which is present in the ore, the entire oxygen would be removed leaving behind the raw base metal. 

In the second stage, the carbon monoxide reacts with the ore, where it attaches itself to another oxygen atom that finally releases carbon dioxide. It becomes necessary to use flux such as limestone as most of the earth is in its impure form in order to remove the accompanying rock gangue and slag. This is known as a calcination reaction that often removes carbon dioxide. Also, the process of electrolytic reduction of aluminium is generally referred to as aluminium smelting.

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Smelting Process

Usually, smelting means the extraction of metal from its ore by the process that involves heating and melting at the same time. The process of smelting is much more than just melting the metal out of its ore. Most of the ores are the chemical compounds of metals and other elements such as oxygen, where the ore is present as an oxide, sulphur, where the ore is present in the form of sulphide or carbon, and oxygen together results in the formation of carbonate. 

The worker has to make the compounds undergo a chemical smelting reaction to extract these metals. Therefore all the smelting processes such as iron smelting, aluminium smelting, copper smelting and other such base metal smelting use suitable reduction substances that combine with the oxidising elements to ultimately free the metal. The process usually takes place in three steps which are roasting, reduction, and fluxes.

1. Roasting: Roasting is a process followed in the case of sulfides and carbonates that removes the unwanted carbon or sulphur and leaves behind an oxide that can directly be reduced. Roasting is usually carried out in an oxidising environment. A few examples of roasting are as follows:

• A common ore of copper known as Malachite is primarily copper carbonate hydroxide Cu2(CO3)(OH)2. Between 250 degrees centigrade and  350 degrees centigrade, the mineral ore undergoes decomposition to copper oxide (2CuO), carbon dioxide (CO2) and water (H2O) in several stages. Later the water and carbon dioxide is expelled into the atmosphere leaving behind the copper (ll) oxide, which is then directly reduced to copper by the reduction process.

• The most common ore of lead is known as Galena which is primary lead sulphide (PbS). Lead sulphide is initially converted into lead sulphite (PbSO3) by oxidation reaction, which then thermally decomposes into lead oxide, and Sulphur dioxide gas is released. After the sulphur dioxide gases are expelled, the lead oxide is reduced, as mentioned below in the reduction process.

2. Reduction: The final step in the smelting process is applied to convert the oxides to elemental metals. A reducing environment that is made by the combustion in the furnace that is air starved is given by carbon monoxide to take out the oxygen atom finally from the molecule of the raw metal. In terms of the absolute temperature and in terms of the melting point of the base metal, the required temperature varies over a large range.  

After the reduction step is completed, Flux and slag can provide a secondary service. They are said to be providing a molten cover over the purified metal that prevents the contact of the metal from the oxygen as the metal still remains hot to easily get oxidised. This also prevents the impurities from developing in the metal. For instance:-

• At roughly 1250 °C, iron oxide becomes the metal iron where the absolute temperature is almost 300 degrees below the iron’s melting point, which is equal to 1538 °C (2800.4 °F or 1811.15 K).

• At roughly 550 °C, mercury oxide becomes vapour mercury where the absolute temperature is almost 600 degrees above the melting point, which is equal to  -38 °C (-36.4 °F or 235.15 K).

3. Flux: Flux is used by metal workers in smelting for various purposes. The most common of them is catalysing a reaction and chemically binding the impurities and the reaction product with the metal. Calcium that undergoes oxidation in the form of lime is often used for this purpose. As it has the capability to react with the carbon dioxide and sulfur dioxide that is produced during the stage of roasting and smelting so as to keep them out of the working environment. 

Environmental Impacts

The smelting industry has a serious effect on the environment that produces a lot of slag and wastewater is released into the environment along with toxic metals such as copper, silver, iron, Cobalt and selenium into the atmosphere. This melting industry is also known to be releasing toxic gas such as Sulphur dioxide that contributes to acid rain which in turn acidifies the soil and water.  Some of the environmental impacts are as follows:-

1. A staggering amount of toxic air pollution is emitted by the copper smelters in the United States. More than 50 tons of lead, 30 tons of arsenic, and 20 terms of selenium are emitted each year into the atmosphere. In the towns of Winkleman and Hayden of Arizona, the ambient arsenic level is more than 150 times higher than Arizona’s health guidelines, where only two smelters are operating currently. There the cancer risk for the people living in those towns has been estimated to be one in hundred in hundred by EPA.

2. The gasification product suggests benzene cyanide ammonia, naphthalene anthracene phenol, and cresols are the toxic gasifica
   tion products discharged by iron and steel, which forms wastewater pollutants. The above-mentioned elements and the range of more complex organic compounds collectively known as polycyclic aromatic hydrocarbons make extremely toxic wastewater pollutants. The pollutants that are generated by other smelting processes are very much with the base metal ores. For example, aluminium smelting typically generates fluoride, benzo(a)pyrene, antimony and nickel along with aluminium. Copper smelting usually discharges cadmium, zinc, lead, arsenic and nickel in addition to copper.

3. The labourers who are working in the smelting industries are reported to be developing respiratory illness that inhibits their ability to perform physical work ok in the smelting industry that is demanded by their jobs. 

Sodium phosphate refers to a group of chemical compounds. The phosphate atom holds three other atoms too. When it holds three hydrogens, it becomes phosphoric acid. Similarly, one hydrogen and two sodium give out disodium hydrogen phosphate, or three sodium can get you trisodium phosphate. When it holds two hydrogens and one sodium, you call it sodium dihydrogen phosphate. You can also call it monobasic sodium phosphate. It’s a chemical compound with a formula – NaH2PO4. It gets produced from the reaction of a little sodium hydroxide and phosphoric acid. In this article, you can get a whole lot of information about sodium dihydrogen phosphate. 

 

What is Sodium Dihydrogen Phosphate?

Sodium dihydrogen phosphate, also known as monobasic sodium phosphate, is an inorganic compound. Monosodium phosphate is another name for the same. Its chemical formula is NaH2PO4. Also, it’s a glycerol derivative obtained by reacting mono and diglycerides, which get derived from edible sources with phosphorus pentoxide. Further, it gets followed by neutralization with sodium carbonate. 

 

NaH2PO4 is a soluble form of phosphate which can get administered intravenously. Below is a structure of sodium dihydrogen phosphate. 

 

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Uses of Sodium Dihydrogen Phosphate

The following are some common uses of the sodium dihydrogen phosphate – NaH2PO4.

• It has numerous applications in water treatment and food industry. It gets used as an emulsifier in products like processed cheese. It also helps as a thickening and leavening agent in baked goods. It controls the pH of the processed foods. 

• It gets added to various goods like toothpaste, evaporated milk, and animal feed. Here also it serves the purpose of a thickening agent and emulsifier. The compound gets commonly used as a sequestrant in a variety of foods. 

• It also has a major application in pharmaceuticals. They use sodium phosphate intravenously to serve as an electrolyte replenisher. It also serves as a laxative, whether orally or rectally. Upon oral consumption, it also works as a urinary acidifier and helps prevent kidney stones. 

• In medicine, it also gets used for constipation as well as preparing the bowel for clinical treatments. At some places, people use it to detect the availability of magnesium ions in salts.   

 

Physical Properties of Sodium Dihydrogen Phosphate 

• The chemical compound, NaH2PO4, appears in the form of white powder or crystals. It is odourless as well. 

• When it comes to the solubility of the compound, it’s soluble in water and insoluble in alcohol. It has a melting point of 212.00 Celsius. 

• Its complexity is 61.9, and pH levels are 8.0 and 11.0. The molecular weight or molar mass of the compound is 119.98 g/mol. 

 

Chemical Properties of Sodium Dihydrogen Phosphate

NaH2PO4 + NaOH   →  Na2HPO4 + H2O

NaH2PO4 + HCI      →      H3PO4 + NaCl 

What is Sodium Phosphate? 

• Sodium phosphate and polyethylene glycol have been analyzed in 94 grown-ups going through colonoscopy. 

• Polyethylene glycol caused huge decreases in serum potassium, calcium, phosphorus, magnesium, bicarbonate, and blood urea nitrogen, and expansions in sodium and phosphate. 

• The corresponding changes in the people who utilized sodium phosphate were more noteworthy. Specifically, in 37 of the patients who utilized sodium phosphate and 11 of the individuals who utilized polyethylene glycol, phosphate focuses expanded by more than 5%. 

• Patients who took polyethylene glycol revealed more unfavorable responses, including queasiness, retching, stomach spasms and distension, butt-centric bothering, restlessness, and chills. 

• These side effects were additionally found in the sodium phosphate bunch, however essentially now and again. 

• The creators prescribed that while sodium phosphate appeared to be more satisfactory to patients, it ought to just be utilized with clinical management and in the wake of screening cautiously for cardiovascular, hepatic, and renal infection, and ought not be utilized with prescriptions that would intensify electrolyte aggravations, like diuretics, or with drugs that electrolyte unsettling influences would influence, like digoxin and lithium.

In 340 patients going through elective colonoscopy, sodium phosphate was contrasted and polyethylene glycol with added ascorbic corrosive. Polyethylene glycol was basically just about as useful as sodium phosphate. Of all unfavorable occasions announced five were in the individuals who took polyethylene glycol and 24 in the people who took sodium phosphate. The most widely recognized in the previous was retching and in the last hyperphosphatemia and hypokalemia; two instances of hypokalemia were named not kidding.

Drug Studies

Observational Examinations

In 194 patients randomized to get either sodium Pico sulfate or armada phosphate soft drink before barium bowel purge, there was no distinction in the nature of gut readiness, yet Pico sulfate was simpler to take and better tasting furthermore it incited less sickness and regurgitating.

Near Investigations

Sodium phosphate and polyethylene glycol have been thought about in 94 grown-ups going through colonoscopy. Polyethylene glycol caused critical decreases in serum potassium, calcium, phosphorus, magnesium, bicarbonate, furthermore blood urea nitrogen, and expansions in sodium and phosphate. The corresponding changes in the people who utilized sodium phosphate were more noteworthy. Specifically, in 37 of the patients who utilized sodium phosphate and 11 of the people who utilized polyethylene glycol, phosphate focus
es expanded by more than 5%. Patients who took polyethylene glycol detailed more antagonistic responses, including queasiness, retching, stomach issues and distension, butt-centric disturbance, restlessness, and chills. These manifestations were likewise found in the sodium phosphate bunch, however fundamentally now and again. The creators suggested that while sodium phosphate appeared to be more OK to patients, it ought to just be utilized with clinical oversight furthermore subsequent to screening cautiously for cardiovascular, hepatic, also renal infection, and ought not be utilized with meds that would worsen electrolyte unsettling influences, such as diuretics, or with drugs that electrolyte aggravations would influence, like digoxin and lithium.

In 340 patients going through elective colonoscopy, sodium phosphate was contrasted and polyethylene glycol with added ascorbic corrosive. Polyethylene glycol was at least as strong as sodium phosphate. Of all unfavorable occasions revealed five were in the people who took polyethylene glycol and 24 in the people who took sodium phosphate. The generally normal in the previous was heaving and in the last option hyperphosphatemia and hypokalemia; two instances of hypokalemia were named not kidding.

Deliberate Audits

Three sorts of entrails arrangements for colonoscopy

(Sodium phosphate, polyethylene glycol, and sodium Pico sulfate) have been analyzed in a meta-investigation of 29 preliminaries in a sum of 6459 patients. Sodium phosphate was the best at purifying the colon and was preferred endured over polyethylene glycol. Sodium picosulfate had comparable adequacy to polyethylene glycol. There were antagonistic occasions in 1054/1662 patients who took polyethylene glycol and 902/1590 who took sodium phosphate.

More patients created unsteadiness with sodium phosphate than polyethylene glycol, stomach torment was more normal with polyethylene glycol, and the two gatherings had comparative measures of queasiness, retching, and perianal torment. When polyethylene glycol was contrasted and sodium pico sulfate (104 and 112 patients individually) polyethylene glycol delivered more queasiness, spewing, stomach torment, rest aggravation, and perianal bothering than sodium

Pico sulfate; 71% of patients who took polyethylene glycol revealed unfriendly occasions contrasted and 48% of the individuals who took sodium picosulfate. In examinations of sodium phosphate and sodium picosulfate, there were comparative sums of sickness, spewing, discombobulation, and stomach torment.

Organs and Systems

Endocrine

A 39-year-elderly person with oncogenic osteomalacia brought about by an osteosarcoma of the right scapula created tertiary hyperparathyroidism in the wake of taking oral phosphate also nutrient D. The uniqueness of this case was the conjunction of hyperparathyroidism and oncogenic osteomalacia. All patients recently detailed as having created tertiary hyperparathyroidism with phosphate supplements had taken them for 10–14 years before finding, however this patient had taken it for just 2 years. The proposed instrument is that exogenous phosphate animates parathyroid movement through sequestration of calcium.

Electrolyte Balance

From 1987 to October 31, 2001 the Canadian Adverse

Drug Reaction Monitoring Program got 10 reports of genuine electrolyte aggravations (hypernatremia, and hypokalemia), just as hypocalcemia and hyperphosphatemia, acidosis, parchedness, renal deficiency, and tetany in patients who had taken in excess of 45 ml of the arrangement, in patients in danger of these inconveniences, and additionally in patients involving various laxatives for inside readiness. Taking into account these reports, Johnson and Johnson,

Merck Consumer Pharmaceuticals, and Pharma science.

Sodium sulfide, or Na2S, is an inorganic chemical compound with the formula of Na2S that has risen to prominence in the organic chemical industry. It’s a powerful alkaline solution that smells like rotten eggs when exposed to moist air. Despite the fact that the solid-state is yellow, the solution is colourless. It’s usually labelled as “sodium sulfide flakes” in the grades.

Sodium sulfide is a salt which plays an essential role in the organic chemistry industry. The formula for sodium sulfide is Na2S, or more commonly its hydrate Na2S·9H2O. Both the anhydrous and the hydrous salts are colourless solids. Sodium sulfide is a water-soluble compound, with a strongly alkaline solution. If the compound is exposed in the moist air, Na2S and its hydrates emit hydrogen sulfide. This emission smells like a rotten egg. The solid-state of sodium sulfide in solution is a yellow colour, and it comes as grades, known as sodium sulfide flakes. The IUPAC name of sodium sulfide is disodium sulfide. The oxidation number of sodium sulfide is -2, whereas its pH value is 10.4.

 

IUPAC Name – Sodium Sulfide

Sodium Sulfide Structure – Na₂S

Na2S adopts the antifluorite structure.  This structure is obtained by exchanging the positions of anions and cations. This means that the Na+ occupy sites of the fluoride and  S2- hold the sites for Ca2+.

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Sodium Sulfide-Na₂S Chemical Information

 

Sodium Sulfide – Na₂S – Physical Properties

 

 

Sodium Sulfide – Na₂S – Chemical Properties

Sodium sulfide dissolves in water and forms the ions it needs. The following is the reaction.

Na2S + H2O → 2 Na+ + HS– + OH–

When heated, it quickly oxidized to generate sodium carbonate and sulphur dioxide.

2Na2S + 3O2 + 2CO2 → 2Na2CO3 + 2SO2

Polysulfides are formed when it reacts with sulphur.

2Na2S + S8 → 2Na2S5

Na2S + H2O → 2 Na+ + HS– + OH–

2Na2S + 3O2 + 2CO2 → 2Na2CO3 + 2SO2

Na2S + 4 H2O2 → 4 H2O + Na2SO4

2Na2S + S8 → 2Na2S5

 

How is Sodium Sulfide Produced?

In industries, Na2S is produced by a carbothermic reduction reaction. In this reduction reaction, carbon is used as a reducing agent.

Similarly, for sodium sulfide, sodium sulfate is reacted by coal. 

Na2SO4 + 2 C → Na2S + 2 CO2 

In laboratories, t
he sodium sulfide salt is usually prepared by the reduction method. Sodium sulphur is reacted by anhydride ammonia, or through sodium in dry THF, with the help of naphthalene as a catalyst. The result formed will be sodium naphtha lenoide.

2Na + S → Na2S

 

Sodium Sulfide (Na₂S) has a Variety of Applications

• It is employed as an oxygen scavenger and a metal precipitant in water treatment.

• Used as a bleaching agent in the textile sector to preserve developer solutions from oxidation in the photographic business.

• It’s used to make elastomeric synthetic materials, sulphur colours, and other things.

• In the crafting process, it’s mostly used in the pulp and paper sector. It improves the sulphate cooking process’ selectivity and speeds up the delignification process.

Uses of Sodium Sulfide

• In the paper and pulp business, it’s used in the kraft process.

• In water treatment, it’s used as an oxygen scavenger.

• In the textile sector, it is used as a bleaching agent.

• Sodium sulfide is mainly used in the pulp and paper industry for the kraft process. As in the kraft process, wood is converted into wood pulp, sodium hydroxide and sodium sulfide help to dissolve the lignin of wood fibre.

• This compound is used in water treatment. In this method, sodium sulfide acts as an oxygen scavenger agent

• For chemical photography, sodium sulfide is used as a metal precipitant for toning black and white photographs

• In the textile industry, sodium sulfide is used as a bleaching agent, dechlorinating agent and also desulphurising agent.

• In the production of rubber chemicals, sulfur dyes and other chemical compounds are used.

• Used in various applications like ore flotation, dye-making, oil recovery and detergent. 

Safety Measures: 

• Used as an unhairing agent in the liming process during leather production.

• Because sodium sulfide is a strong alkaline, it causes skin burns.

• When sodium sulfides combine with acid quickly, it produces poisonous hydrogen sulfide.

Side Effects of Sodium Sulfide

It’s normal for the top layer of skin to peel slightly. Irritation, redness, and scaling of the skin are also possible side effects. Stop taking this medication and inform your doctor or pharmacist right away if any of these effects persist or worsen.

Keep in mind that your doctor ordered this medication because he/ she believes the benefit to you outweighs the risk of adverse effects. The majority of people who take this medicine do not have any substantial adverse effects.

Sodium sulfide is strongly alkaline. It can cause significant skin burns. Reacting with acid can form hydrogen sulfide, which is a highly toxic and flammable gas. In reduced ventilation spaces, hydrogen sulfide accumulates at the bottom. To use hydrogen sulfide, one should keep the safety data sheet with them.

Na2S + 2HCl → 2NaCl + H2S(g)

 

What’s the Type of Bonding of Sodium Sulfide? 

Sodium sulfide compound is an ionic compound. There are 2 Na atoms per 1 Sulfide atom. It has a central Sulfur atom encircled by 4 Oxygens in covalent bonds.  The Sodium atoms and Sulfur or Oxygen atoms in the compound exchange their electrons. Moreover, Sulfur is in group 6, and it requires two more electrons to attain a noble gas state of Argon.

 

Likewise, the remaining 2 Sodium atoms want to lose 1 electron each to become the noble gas state of Neon. Thus, the 2 Sodium atoms each provide one electron to the Sulfur atom, helping it to be stable in its outer shell.

 

Since the Sodium atoms give away all its extra electrons to its outermost shell, the two atoms attain the noble gas configuration of Neon and hence become stable.

Heat of Fusion and Heat of Vaporization

The latent heat of fusion is also called as the enthalpy of fusion. It refers to the amount of the energy which needs to be supplied to a solid, generally in the heat form. This aids in triggering a change in the physical state and, in turn, converts it to a liquid. Consider, for example, the specific heat of fusion of water of 1 kg, which refers to the amount of the heat energy which needs to be supplied for converting 1 kg ice without a change in the temperature is known to be 333.55 kJ.

The heat of solidification is known to be the opposite of the latent heat of fusion. The value of the heat of solidification for a substance is equal in the magnitude of the specific latent heat of fusion but has an opposite sign. Consider, for example, that the amount of the energy which is absorbed by the ice for changing to water is always equal to the amount of the energy which is liberated by water for turning into ice.

The latent heat of fusion for a substance is also regarded as the energy which is needed for accommodating an increase in the volume of the given substance after it undergoes a change in its physical change. Melting point is known as the temperature at which any given substance tends to undergo a transition in its phase. When the heat of solidification is considered, this temperature is also called as the freezing point of the given substance. The environmental pressure is assumed to be always 1 unless it is specified.

Specific Heat of Fusion and Molar Heat of Fusion and Vaporization of Water

The specific heat of fusion is similar to the latent heat of fusion since the melting of a given solid at normal pressure generally needs heat energy. Consider, for example, specific latent heat of ice. It is the change in the heat of ice when it changes from solid to liquid, that is, ice to water.

If one unit mass of the given substance is taken into consideration, the energy which is needed for converting it to the liquid state when pressure is kept constant, it is known as the specific latent heat of fusion for that particular substance. However, if the change in the heat is to be calculated per mole basis, this latent heat of fusion is called the molar heat of fusion of that substance. 

Since liquids tend to possess a higher amount of internal energy which is associated with them when compared to the solids, some amount of energy has to be supplied to the solids for facilitating its melting. Similarly, some energy gets released by the liquids when they turn into solids. The particles or the molecules which make up the liquids have higher potential energy because they are held together by weaker intermolecular forces of attraction. Hence, the energy which is needed for dissociating the intermolecular forces between the liquid particles is lower when compared to that of the solids.

One such example of the latent heat of freezing is observed when water is cooled. When it is initially in the solid-state, it cools to the temperatures below 0 ⁰C and the temperature of water steadily drops till it reaches 0 ⁰C. However, at this point water crystallizes and forms ice. Once it turns into ice and is entirely frozen, the temperature of ice drops below 0 ⁰C as it cools further.

The specific latent heat of fusion is always a positive value, except for the case in helium. Below 0.3 K temperature, which is almost absolute zero, the isotope of helium, helium-3 contains a negative value of the specific latent heat of fusion. 

In 1885, Adolf Baeyar theorized on how to create stability of the first few cycloalkanes, which was derived from the idea that in tetrahedral geometry, there’s a normal angle between a pair of carbon atom bonds in 109.28′ metal molecules. In the subject of Tetrahedral Geometry, this concept became very vital and helped us find out that the bond angle for carbon atoms is 109.28′ (or 109.50) methane molecules. Baeyar also found out that these cycloalkanes have distinct bond angles and also different properties and stability at the same time. This is when, based on this, he first thought of proposing Strain Theory.

Overview of Strain theory

This theory, when published, described the cycloalkane reactivity and its stability in great depths. It also told us that the optimum overlap of atomic orbitals is achieved for a bond angle of 109.50. So in a gist, from this theory, we can conclude that this is the best bond angle for alkanes.

This abundantly efficient and preferable overlap of atomic orbitals gives results where we achieve the highest bond strength and the vastly stable molecule.

The rings in this experiment cause distress on the bond angles as they deviate from the ideal. This also helps us observe that the higher the pressure, the more unstable the system is. Such a higher strain concludes in an increase in reactivity and heat combustion. As Baeyer stated, if we deviate from the bond angle from the perfect bond angle value, which is 109.50, it will create a strain in the molecule. This will result in a lower variance and a much less unstable solution.

Assumptions of strain theory

This theory is founded on the following assumptions:

• Planar Rings are utilized in all of the ring structures. Unstable Cycloalkanes originate due to divergences from the general tetrahedral angles.

• Large Ring Structures contain negative strains, but these do not exist.

• Since these cycloalkanes have carbon rings with a puckered texture instead of a planar(flat) structure, their bond angles are around 109.50 or less—for example, Cycloheptane, Cyclooctane, and Cyclopentolate.

• These assumptions form the ground basis for comprehending the instability in the cycloalkane ring system.

Baeyer’s Strain Theory in Cycloalkanes

• When carbon gets bound to two other carbon atoms in propane, which is an open-chain compound, it is s sp3  hybridized; these hybrid orbitals are usually utilized to form strong sigma bonds.

• Since these carbon atoms are present in the cyclopropane, they do not use these hybrid orbitals to form any bonds; their bent-bond is weaker than a general carbon to carbon bond. This strain is known as the angle strain.

• This ring produces strains with bond angles that deviate from the ideal. We can observe that higher strains result in increased volatility, combustion of heat and reactivity. In simple words, the deviation is directly related to the instability.

• By assuming this, Baeyer discovered that a number of cycloalkanes have different types of bond angles and different properties and stabilities.

• He proposed that the angle in the strain theory is based on this and this theory describes the stability and reactivity.

• The cyclopropane ring is in the shape of a triangle and has a standard tetrahedral structure where the angle is between the two bonds that are compressed to 60oand each of these bonds involved is pulled in by 24.75⁰.

• What happens is that all three angles become 60o instead of109.5o, which is the normal bond angle for a carbon atom.

• The deviation or Angle strain of each and every bond is defined by the value of 24.75⁰.

• In the same way, a cyclobutane is a square with the bond angles of 90⁰ and not 109.5⁰ to make the ring system square with an angle strain of 9.75⁰.

• When we talk about the cyclopropane and cyclobutane ring systems, a ring pressure is caused by a usual tetrahedral angle.

• In contrast to this Baeyer believed that cyclopropanes are highly stressed and unstable compounds. 

• As a result, the triangle ring can be opened up even with a slight provocation, with a release of tension with them. This is true as the cyclopropane undergoes Br₂ ring-opening reactions.

• Cyclopentane, on the other hand, is known to be the least stressed and the most stable. This is why it also has no ring-opening reactions.

• In Cyclohexane, the strain angle is bigger than it is in cyclopentane. This states that if the number of the ring increases, the strain increases with it.

• So, in theory, cyclohexane and higher cycloalkanes become more reactive and unstable as time passes. 

• But in contrast to this prediction, cyclohexane and the members of this group turned out to be highly stable, which meant that they go through substitution instead of additional reactions. 

As a result, this hypothesis only accounts for the first three adequately. Hence, Cyclopentane > Cyclobutane > Cyclopropane

Limitations

• The Baeyar was not able to describe the impact of an angle pressure in the larger structures.

• According to him, cyclohexane is less stable than cyclopentane, but the reality is the opposite of this.

• He stated that due to negative pressure, larger ring structures are not possible, but they do exist and are highly stable.

• For the removal of angle pressure, larger ring structures are wrinkled (puckered) instead of being planar (flat).

Did You Know?

Simple and larger cycloalkanes are very stable, similar to alkanes, and their reactions, such as radical chain reactions, are similar to alkane reactions. Due to Baeyer strain and ring strain, small cycloalkanes, especially cyclopropane, have lower stability. They react in the same way as alkenes, but instead of electrophilic addition, they react in nucleophilic aliphatic substitution. Ring-opening or ring-cleavage reactions of alkyl cycloalkanes are these reactions.

 

A Diels–Alder reaction followed by catalytic
hydrogenation may produce cycloalkanes. Medium rings have higher rates in nucleophilic substitution reactions but lower rates in ketone reduction. This is due to the conversion of sp₃ to sp₂ states, or vice versa, and the preference for the sp₂ state in medium rings, which relieves some of the unfavorable torsional strain in saturated rings. Many redox or substitution reactions have linear associations with strain energy differences SI between an sp₂ and sp₃ state measured using molecular mechanics.

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What is Sucrose?

Sugar or plain sugar or cane sugar, whatever the name, is such an important item that adds some sweetness to your life and taste in the kitchen. The chemical name of this sugar is sucrose. In general, we have different types, uses, etc for sugar, sucrose has a chemical formula, meaning, physical and chemical properties based on its structure, etc. Let’s have a detailed explanation about sucrose.

The chemical formula for sucrose is C12H22O11. The sucrose meaning can be constituted by the structure and arrangement of sucrose molecules. It is a molecule connected with both glucose and fructose with the help of glycosidic bonds. 

In 1857, William Miller had found the molecule of sucrose and coined the term. The refined form of sucrose is nothing but sugar which can be used in several recipes to add sweetness to them.

Structure

As glucose and fructose are two monosaccharides, sucrose can be considered disaccharides. The disaccharides sucrose can be obtained by the linkage of the able molecules. This can be done with the help of glycosidic bonds. So the linkage is also known as glycosidic linkage. The structure of the sucrose is Crystal form and it is soluble in water. Sweetness is the basic feature of sucrose. The chemical structure of sucrose can be shown below. 

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Monosaccharides and disaccharides are two categories of sugar.

Features of Sucrose

• The Chemical Formula of Sucrose is C12H22O11.

• It has a Molar Mass or Molecular Weight of 342.30 g/mol.

• The Density of sucrose is 1.587 g/cm3

• Its physical appearance after purification is white, crystalline solid.

• It starts decomposing at 459 K.

Sucrose in Plants

There is a predominant role of sucrose in plants. Sucrose will act as an essential career of carbon for the plants as it is a carbohydrate. Also, the solubility nature of sucrose in water gives it a stable structure. The plant cells help to send the sucrose to the phloem with the support of special vascular tissue. 

Differentiation Between Glucose, Fructose, and Sucrose

All three cases, sucrose, fructose, glucose, and all types of sugar have few differences. They are as follows- 

• Glucose has the least sweetness when compared to fructose and sucrose. Sucrose is sweeter than glucose and less sweet than fructose. Fructose is the sweetest of the other two.

• Glucose is available in processed foods to add a sweet taste to them. It is like a carbohydrate-based food. It has both good and bad effects on the body. Whereas fructose is known as fruit sugar. It can be found in real fruits and vegetables. As it is a natural source of sucrose, it doesn’t have much negative effect on the body.

• Sucrose, glucose, fructose may differ in absorption and digestion also. As sucrose is a disaccharide, it can be broken down into different molecules, and then only it can be absorbed by the body. It is a longer process. But the separation starts from the mouth itself. 

• The glucose can be easily digested and absorbed by the body directly from the liner of the small intestine. It is used widely to improve energy and to raise the blood sugar level in the human body. Whereas fructose can be digested and absorbed a bit easier than sucrose but takes time when compared to glucose. Because the factors need to convert into glucose form they only can be absorbed by the body.

Accumulation of Sucrose 

The process of accumulation of Sucrose in sugarcane is a step-by-step process. It can be done with the help of the photosynthesis process. The sucrose can be transported into the stem with the help of the following. If the sucrose can be stored in the stem, it can be extracted during the last phase. Also, there is another possibility that the sucrose can be stored in the stem or can be transferred to other parts which give rise to new growth. It has both pros and cons. If the new growth starts, it leads to another cycle of photosynthesis. But the amount of sucrose available in the stem gets reduced. The entire process of extracting sucrose in sugarcane can be shown below.

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Bottom Lines

The use of sucrose can be found in preparing several food recipes. These food items became a livelihood for many people. The use of sucrose is also found in some chemical reactions. Hence the sucrose is a disaccharide molecule with a combination of both glucose and fructose. 

Journey of Sucrose: Then and Now

Before we highlight different milestones associated with the journey of sweetness and sugar and our inner cravings for it, we should have some established definitions in our minds. Carbohydrates might be simple or complex, these are known as the micronutrients that we require for our bodies as a main energy source. 

Simple carbohydrates oe the sugar that is single such as galactose, glucose, and fructose also offers the foundation for a double sugar such as table sugar (sucrose) and complex sugars such as starch. The digestive carbohydrates that we eat, will break down gradually into one of the three molecules also known as small sugar units that are absorbed easily by our intestines. 

Our ancestors also used to eat sweet foods like dates, wild fruits, and honey for obtaining sweetness. Honey used to be the initial sweet agent that has been explored by humans. It is believed that this was explored by Egyptians. They discovered it in the form of wild honey and decided to gather it. They collected it after getting to know the fact that it will offer them pleasure and energy. 

Once they got to know the production methods, they started keeping the bees for the production of honey. The next source was a condiment, yes you got it right it was sugarcane. This originated in the parts of Asia. Initially, Arabs conducted the extraction and refinement of Sucrose and they made it popular via trade. 

This exploration took a shape of intensity as Europeans went for establishing huge sugarcane plantations in the Caribbeans and Pacific colonies. And, it was also a huge reason for transatlantic slavery. After the European conflicts, French people picked another path and began to extract sucrose via su
gar beets and they also cultivated it as a sigarcase substitute. This is a story of the 19th century that played a key role in increasing the production of sugar as later transformed into sweeteners (primarily corn-related sweeteners). Today, the sucrose history seems to be intertwined with the destruction of the ecosystem due to the result of deforestation for the sake of developing sugar plants and it is having negative results on public health. 

After knowing the detailed history of sugar, the production and consumption style were the factors that contributed to the sugar cravings. And, it resulted in both social, environmental, and health subjects. Fruits and plants are the main sources of sugar that is said to be natural, and for these, our ancestors also craved them. This is because they considered it a great energy source. And, they transferred this sweet tooth to their coming generations as well. But, we need to understand that we do not require the same amount of calories that our ancestors required as they used to do more physical tasks than we do these days.