Carbon and Its Compounds Class 10 Notes: CBSE Science Chapter 4

Hydrocarbons – Carbon and hydrogen-based compounds

Organic Compounds- Hydrocarbons and hydrocarbon-derived chemicals

Bonding in Carbon - The Covalent Bond:

Covalent Bond:

"The force of attraction originating from mutual sharing of electrons between the two atoms" is how a covalent bond is defined. One, two, or three pairs of electrons may be shared by the combining atoms. The covalent bond is established by the mutual sharing of electrons between two similar or dissimilar atoms, which contributes to the stability of both atoms. When two atoms join through mutual electron sharing, each atom does so to get a stable configuration of the nearest noble gas. A covalent bond is shown by a tiny line (-) connecting the two atoms. Covalent compounds are those that form because of covalent bonding.

Properties of Covalent Compounds:

• Covalent substances don't exist as ions, but rather as molecules.

• They exist as liquids or gases at normal temperatures. A few chemicals, such as urea and sugar, do exist in the solid-state.

• Covalent compounds have low melting and boiling points in general.

• In water and other polar solvents, covalent compounds are often insoluble or less soluble.

• When fused or dissolved, these materials are poor conductors of electricity.

• The covalent bond is directed in nature since it is formed between the nuclei of atoms.

• There are several ways to generate a covalent bond. A'single covalent bond,' or simply 'a single bond,' is defined as a bond created by the mutual sharing of one pair of electrons. The term "multiple covalent bond" refers to a link formed by the mutual sharing of more than one pair of electrons. A double covalent bond or a triple covalent bond are examples of such bonds.

Types of Covalent Bonds: 

1. Single Bond:

Hydrogen Molecule:

The outermost shell of a hydrogen atom has just one electron, and it takes one more electron to achieve the nearest noble gas configuration of helium (\[{\text{He:1s 2}}\]). To do so, two hydrogen atoms each donate one electron, allowing them to share one pair of electrons. The two hydrogen atoms create a single covalent bond because of this process.

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Chlorine Molecule

The valence electrons on the chlorine atom are seven. As a result, each Cl atom requires an additional electron to achieve the nearest noble gas configuration \[{\text{(Ar: 2, 8, 8)}}\]. They accomplish this by sharing one pair of electrons, as seen below.

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2. Double Bond: 

Oxygen Molecule

The valence shell of an oxygen atom has six electrons. As a result, the nearest noble gas arrangement requires two additional electrons. This is what happens when two oxygen atoms share two pairs of electrons:

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3. Triple Bond 

Nitrogen Molecule

The valence shell of a nitrogen atom has five electrons. Three more electrons are required to obtain a stable configuration of the nearest noble gas (neon). As demonstrated below, this is accomplished by sharing three pairs of electrons.

4. Multiple Bonds – 

Multiple bonds are a combination of double and triple bonds.

5. Covalency: 

The number of electrons contributed by an atom of an element for sharing during the formation of covalent bonds is referred to as the element's covalency

6. Tetravalency in Carbon:

The first two shells of a carbon atom have a total of six electrons, with the K-shell having two electrons and the L-shell having four. This distribution shows that there is one fully filled's' orbital in the outermost shell and two half-filled 'p' orbitals in the outermost shell, indicating that carbon is a divalent atom. However, in its combined state, carbon exhibits tetravalency. A carbon atom possesses four valence electrons as a result.

It could gain or lose four electrons to generate the C4- anion or the C4+ cation.

Carbon would be far from obtaining stability under either of these situations, according to the octect rule. To address this issue, carbon undergoes a transformation.

Allotropes of Carbon:

Allotropy: Allotropy is the occurrence of an element existing in different forms with varied physical qualities but same chemical properties, and the various forms are known as allotropic forms or allotropes.

Crystalline Form: Diamond, Graphite

Amorphous Form: Coal, Coke, Charcoal (or wood charcoal), Animal Charcoal (or bone black), Lampblack, Carbon black, Gas carbon, and Petroleum coke are all examples of coal, coke, and charcoal.

Two crystalline allotropes of carbon are diamonds and graphite. Covalent crystals include diamond and graphite. However, their qualities are vastly different.

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Comparison of Diamond and Graphite Properties:

The structural distinctions between diamond and graphite account for these changes in characteristics. Each C atom in diamond is connected to its neighbours by four solitary covalent connections. A three-dimensional network of covalent bonds is formed as a result. The carbon atoms in graphite are organised in regular hexagons in flat parallel layers. Covalent bonds bind each carbon in these layers to three others. As a result, graphite takes on a double bond nature. Weak van der Waals forces bind each layer to its neighbours. This makes it easy for each layer to glide over the other. Because of its structure, graphite is soft and slippery, and it can be used as a lubricant. Because of its mobile electrons, graphite is a good conductor of electricity.

Versatile Nature Of Carbon

Carbon's ability to form a vast range of compounds comes from its unique bonding properties. Carbon can create long chains, rings, and branched structures through catenation. It forms strong bonds with itself and other elements, resulting in a large number of stable compounds. Carbons' four valence electrons enable them to bond with various elements, leading to a diversity of compounds with different properties.

Organic Compounds –

 Carbon and hydrogen compounds.

Organic Chemistry- The branch of chemistry concerned with the study of carbon and hydrogen compounds.

Distinguishing Features of Organic Compounds:

1. Linkage Types — Covalent connections are found in organic molecules, whereas ionic linkages are found in inorganic compounds.

2. Melting and Boiling Values — Because of their covalent nature, organic compounds have low melting and boiling points. Melting and boiling points of inorganic compounds are often high.

3. Solubility - Organic compounds are soluble in organic solvents but not in water.

4. Electrical Conductivity — Organic chemicals conduct electricity poorly, whereas inorganic compounds conduct electricity well.

5. Reaction Nature— Organic reactions are complex and slow, but inorganic reactions happen instantly.

6. Heat Resistance — Organic compounds are less heat resistant than inorganic compounds.

7. Combustibility — When burned, organic compounds are flammable and leave no residue. Combustible inorganic compounds are not combustible.

The Creation of a Huge number of Organic Compounds has Several Causes:

Saturated and Unsaturated Carbon Compounds:

Saturated and unsaturated organic compounds are classed according to whether they contain single or multiple bonds.

1. Saturated Carbon Compounds:

Saturated hydrocarbons are carbon and hydrogen compounds with only one (carbon-carbon) link between neighbouring carbon atoms. Carbon-hydrogen bonds are single covalent bonds as well. Because all four carbon bonds are fully utilised, no more hydrogen or other atoms may bind to it, they are referred to as saturated compounds. As a result, they can only undergo substitution reactions. Open-chain aliphatic hydrocarbons are also represented by them. Alkanes are a type of saturated hydrocarbon.

2. Unsaturated Hydrocarbons

Unsaturated hydrocarbons are carbon-hydrogen compounds with one double covalent connection between carbon atoms (carbon=carbon) or a triple covalent bond between carbon atoms. Because hydrogen atoms do not use all the carbon bonds in these molecules, more of them can be connected to them. As they have two or more hydrogen atoms less than saturated hydrocarbons, they undergo addition reactions (add on hydrogen) (alkanes).

Depending on whether there are double or triple bonds, unsaturated hydrocarbons are classified as 'alkenes' or 'alkynes.'

Properties of Saturated and Unsaturated Compounds:

Classification of Hydrocarbons:

Open chain/Aliphatic/Acyclic Compounds and Carbocyclic Compounds are the two primary groups of hydrocarbons. Alkanes, alkenes, and alkynes are the three types of aliphatic hydrocarbons. Alicyclic and Aromatic Carbocyclic Compounds are two different forms of carbocyclic compounds.

Homologous Series & Nomenclature:

Affinity of Carbon with Other Elements:

Carbon has a high proclivity for creating a wide range of carbon and hydrogen compounds. When one or more hydrogen atoms are substituted by an element such as oxygen, nitrogen, sulphur, or another element, carbon can form bonds with other elements in a hydrocarbon chain if the valency of carbon is maintained. 

A functional group is defined as an atom or a group of atoms that makes a bond with the carbon atom in the chain or ring of an organic compound while exhibiting some unique features. This functional group is thus responsible for the property of the entire organic molecule. 

The element that replaces hydrogen is known as a heteroatom in these compounds. Regardless of the length and type of the carbon chain, these heteroatoms bestow unique qualities to the compound and comprise the functional group. As a result, in an organic complex, a functional group is the location of chemical reaction, and all compounds containing that functional group have similar reactions.

The functional group \[{\text{ - OH}}\] is found in alcohols like methanol and ethanol, while \[{\text{ - COOH}}\] is found in acids like ethanoic acid. The \[{\text{ - N}}{{\text{H}}_2}\] functional group has a fundamental nature. In the following compounds, the functional group is encircled. The single line represents the free valency or group valencies. This valency is used to link the functional group to the carbon chain by substituting one or more hydrogen atoms.

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Homologous Series:

All organic compounds are made up of a chain of carbon atoms that grows in length, with several compounds sharing the same functional groups. A homologous series is a collection of molecules with similar chemical structures. Members of a homologous group have similar chemical features and have similar structures. A 'CH₂' group separates the two consecutive members of the series in their molecular formula.

The Homologous Series has Several Essential Qualities, Including:

• Each component has a comparable functional group and follows a general molecular formula.

• The molecular formula of each successive component differs by one unit of '\[{\text{C}}{{\text{H}}_2}\]'.

• Although all members of the series have identical properties, the extent of the reactions vary as relative molecule mass increases.

• As the relative molecular masses grow, physical properties such as solubility, melting point, boiling point, specific gravity, and others change gradually.

A homologous series of organic compounds is formed by hydrocarbons and their primary subgroups. As an example, the most basic of all hydrocarbons is methane, which has the chemical formula CH₄. A single carbon atom is linked to four hydrogen atoms via single covalent bonds in this molecule. Each shared pair of electrons (bond) is represented by a straight line, and the structure of methane (structural formula) can be stated as follows:

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There are around 60 hydrocarbons of the methane type, which have single covalent connections between their carbon atoms and hydrogen atoms to satisfy the remaining valencies. The following series is created by arranging their molecular formulae in order of increasing number of carbon atoms in their molecules.

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Each member of this series differs from the one before it by a \[{\text{ - C}}{{\text{H}}_{{\text{2 - }}}}\] group increment. As a result, the methane family is a homologous series defined by the formula \[{{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n + 2}}}}\]. The reduction of their corresponding alkyl halides \[({{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n + 1}}}}{\text{X)}}\] can be used to prepare all members of this group. The alkane group is the name for this group. The alkene and alkyne groups are also distinguished by the formulas \[{{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n - 2}}}}\] and \[{{\text{C}}_{\text{n}}}{{\text{H}}_{{\text{2n}}}}\], respectively.

Nomenclature of Carbon Compounds:

"The system of designating a suitable name to a particular carbon compound based on certain rules is known as nomenclature."

Most carbon compounds have one of two names:

• Trivial Names 

• IUPAC Names

Trivial Names:

The common names for carbon compounds are known as trivial names. They are typically derived from the compound's source, such as the name formic acid, which comes from the Greek term "formicus," which means "red ants." The names that came this way were unclear and repetitive.

IUPAC Names

As the number of carbon compounds increased, it became necessary to name them in a more methodical manner. The International Union for Pure and Applied Chemistry (IUPAC) proposed a system for naming carbon-based compounds with valid scientific names. The names derived from their rules are known all throughout the world and are referred to as IUPAC names. The name of a carbon compound has three main parts in this scheme, as shown below:

• Wood Root:

This refers to the number of carbon atoms in a certain molecule. For example, \[{{\text{C}}_{\text{1}}} - {\text{Meth, }}{{\text{C}}_2} - {\text{Eth, }}{{\text{C}}_3} - {\text{Prop, }}{{\text{C}}_4} - {\text{But}}{\text{.}}\]

• Suffix:

The suffix refers to the sort of bond or functional group that exists in the carbon chain.

Example 

'ane' - (single bond)

'ol' for alcohols -(-OH)

'ene' (double bond)

'al' for aldehydes - (-CHO)

'yne' - (triple bond)

'oic acid' for carboxylic acid - (-COOH)

• Prefix:

This indicates the presence and position of other functional groups. For example, the following compound could be called:

Word root: But (C4) 

Prefix: 3, chloro 

Suffix: -ol 

Name: 3-chloro butanol

Carbon atoms are numbered from the functional group's side (-OH in this case). 

Trivial Names, IUPAC Names and Molecular Formula of some Organic:

The following table lists the IUPAC names of various chemical compounds, as well as their trivial names and formulas:

Naming the Compound Containing Functional Group entails the following four steps:

• The present functional group is identified. This allows us to select the proper suffix or prefix. The functional group of the following chemical, for example, is carboxylic acid, while the suffix is oic acid.

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• The length of the functional group's longest continuous chain is determined. In the chemical above, the longest continuous chain has five carbon atoms. As a result, pentane is the base name.

• The chain is numbered using the approach of assigning the lowest possible number to the functional group. The carbon of the carboxylic acid is number one, and the carbon of the branching is number three in the given compound.

• After that, the name is decided. The prefix (\[{\text{C}}{{\text{H}}_{3 - }}\]) at carbon 3 is an alkyl group. In this way, the compound's name is completed (3-methylpentanoic acid).

Isomers and Isomerism:

Isomers are compounds with the same molecular formula but various structural formulas, and the process is known as isomerism.

1. Chain Isomerism:

An isomerism in which the isomers are distinguished by the existence of distinct carbon chain skeletons. n-butane and iso-butane are two examples.

2. Functional Isomerism:

Isomerism in which the structure of the isomers differs because of the presence of distinct functional groups.

Chemical Properties of Carbon Compounds:

The majority of carbon-containing molecules connected with hydrogen, i.e. hydrocarbons, are fuels that emit heat when burned. Natural gas, petrol, gasoline, kerosene, heavy oils, and, more broadly, wood, biogas, charcoal, and coke are all rich sources of carbon molecules that are utilised as fuels.

Combustion:

The burning of a substance is referred to as combustion. It's a highly exothermic process, which means it generates a lot of heat. Heat energy, carbon dioxide, and water are the byproducts of the burning of carbon and its compounds (vapour).

Three basic needs must be present for a fuel to be combusted.

• A Combustible Substance: While all carbon compounds are flammable, diamond carbon is not. Petrol is a flammable liquid.

• Combustion Promoter: Atmospheric air or oxygen gas is a combustion promoter. Combustion will not be possible without them. Combustion is not supported by carbon dioxide or nitrogen gases.

• Heating to Ignition Temperature: For a fuel to catch fire, a certain quantity of warmth or heat is required. Coal has a high ignition temperature, and a matchstick will not be able to light it. A matchstick, on the other hand, can ignite paper or LPG gas due to its low ignition temperature.

When all the above parameters are met in a combustion process, proper combustion (energy production) occurs with the least amount of waste and pollutants. If an ideal fuel such as LPG is available (high calorific value and relatively high levels of branched hydrocarbons), an adequate and continuous supply of oxygen should be maintained to burn it. The combustion will be smooth and complete if the ignition spark or flame is sufficient.

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It generates a lot of thermal energy with no waste of raw materials (unreacted) and no unwanted byproducts (pollutants).

When most carbon compounds, such as hydrocarbons, are burned in air or oxygen, they release a lot of heat, as well as carbon dioxide and water vapour. As a result, they are employed as fuels. In air, methane, for example, burns with a blue flame. When there is sufficient of oxygen available, alkanes burn with a non-sooty flame; nevertheless, when oxygen is scarce, they burn with a sooty flame.

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Methane produces carbon black when there is a scarcity of oxygen.

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Alkenes, for example, are highly combustible and have an explosive reaction with air. They produce carbon dioxide and water vapour by burning with a bright flame.

Cracking and heat breakdown occur in some hydrocarbon molecules. In this process, compounds are heated to high temperatures (500-8000C) in the absence of air, at which point they decompose into a mixture of saturated and unsaturated hydrocarbons as well as hydrogen.

Oxidation:

Carbon:

Carbon undergoes oxidation when it meets oxygen at a higher temperature, resulting in the formation of oxides such as carbon monoxide (\[{\text{CO}}\]) and carbon dioxide (\[{\text{C}}{{\text{O}}_2}\]). When carbon or carbon-containing fuels are burned incompletely, carbon monoxide is produced.

\[{\text{C  +  }}\frac{1}{2}{{\text{O}}_2} \to {\text{C}}{{\text{O}}_{({\text{g)}}}}\]

\[{\text{CO}}\] can be found in automotive exhaust (when incomplete combustion occurs), volcanic gases, chimney gases, and other sources.

Carbon dioxide can be made by completely burning carbon, hydrocarbons, carbon monoxide, and other gases.

$  {\text{C  +  }}{{\text{O}}_{2({\text{g)}}}} \to {\text{C}}{{\text{O}}_{2({\text{g)}}}} + {\text{Heat}}$

$  2{\text{CO  +  }}{{\text{O}}_{2({\text{g)}}}} \to {\text{ 2C}}{{\text{O}}_{2({\text{g)}}}}{\text{  +  Heat}} $

 $ {\text{C}}{{\text{H}}_4}{\text{  +  2}}{{\text{O}}_{2({\text{g)}}}} \to {\text{ C}}{{\text{O}}_{2({\text{g)}}}}{\text{  +  2}}{{\text{H}}_2}{\text{O}} $

Carbon Containing Compounds:

When these are burned in air or oxygen, they undergo oxidation processes. Methane, for example, is oxidised to methanal or formaldehyde when it is combined with oxygen and heated in the presence of molybdenum oxide.

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Carbon molecules are oxidised to produce other carbon compounds with different functional groups, such as alcohol, carboxylic acid, ethers, and so on. An oxygen environment or oxidising agents such as alkaline \[{\text{KMn}}{{\text{O}}_4}\] or acidified \[{{\text{K}}_2}{\text{C}}{{\text{r}}_2}{{\text{O}}_7}\] are used to accomplish oxidation. The oxidation of methane, for example, produces methanol, an industrial alcohol.

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Acetic acid is made by oxidising fermented liquors (10-15 percent alcohol) in the presence of mycoderma aceti in the air. Vinegar is made by diluting acetic acid to a concentration of 3-7 percent.

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When ethene is passed through an alkaline potassium permanganate solution, the permanganate solution's purple colour diminishes.

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Addition Reaction:

Addition reactions are those in which an unsaturated hydrocarbon reacts with another chemical to generate a single product. As an example, 

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Alkenes, which have double carbon bonds, readily react with certain compounds to generate saturated addition products. Halogenation is the process of adding a \[{\text{C}}{{\text{l}}_2}\], \[{\text{B}}{{\text{r}}_2}\], or \[{{\text{I}}_2}\] molecule across an alkene's double bond.

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Hydrogenation is the addition of a hydrogen molecule across the double bond of an alkene to produce saturated products. This occurs in the presence of nickel, the catalyst.

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Unsaturated compounds with double bonds are found in vegetable oils such as ground nut oil, cotton seed oil, and mustard oil. At room temperature, they are liquids. Saturated compounds called vanaspati ghee or vegetable ghee result from hydrogenation at the double bonds. At room temperature, these are

solids.

\[{{\text{R}}_2}{\text{C = C}}{{\text{R}}_2} + {{\text{H}}_2} \to {{\text{R}}_2}{\text{CH}}{\text{.CH}}{{\text{R}}_2}\](where Ni is present at high temperatures and pressures)

Substitution Reaction:

Substitution reactions occur when one or more atoms or groups of atoms in a molecule are replaced or substituted by other atoms or groups of atoms. As an example,

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The hydrogen in an alkane molecule is changed by another atom or a group of atoms (such as alkyl) in substitution processes, resulting in the production of derivatives of that hydrocarbon. Halogenation is the process of replacing an atom with a halogen atom. Chlorination, bromination, or iodination are the outcomes of this sort of replacement.

Some Important Carbon Compounds:

Ethanol or Ethyl Alcohol:

The term 'alcohol' usually refers to ethanol. For thousands of years, man has used ethanol, particularly in the form of wine.

The following is ethanol's structural formula:

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It has the following molecular formula: \[{\text{C}}{{\text{H}}_3}{\text{C}}{{\text{H}}_2}{\text{OH}}\] or \[{{\text{C}}_2}{{\text{H}}_5}{\text{OH}}\]

• Ethanol is a colourless liquid with a pleasant odour, with a boiling point of 78 degrees Celsius and a freezing temperature of -114 degrees Celsius.

• It dissolves in water as well as practically all organic solvents.

• It is highly intoxicating in nature.

• It is flammable and produces a blue flame when burned.

Properties of Ethanol:

Action with Sodium Metal:

When a bit of salt is placed into ethyl alcohol, hydrogen gas bubbles are visible.

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Action with Phosphorus Trichloride:

Ethanol forms ethyl chloride when it interacts with phosphorus trichloride.

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Action with Concentrated Sulphuric Acid:

When ethyl alcohol is treated with concentrated \[{{\text{H}}_2}{\text{S}}{{\text{O}}_4}\] at \[{170^0}{\text{C}}\], it dehydrates and forms ethane.

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Diethyl ether is a pleasant-smelling chemical that occurs at a lower temperature of \[{140^0}{\text{C}}\] and when ethyl alcohol is present in excess.

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Acidified Potassium Dichromate Oxidation of Ethyl Alcohol:

Aldehydes are formed when alcohols are oxidised. Further oxidation of the aldehydes produces carboxylic acids.

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Uses:

These are all essential chemical compounds that are employed in the chemical industry.

• Many organic solutes, especially those that are insoluble in water, are dissolved in ethyl alcohol.

• It's utilised in the manufacture of perfumes.

• It's utilised in the production of gasohol, which is a 90 percent petrol (gasoline) and 10% ethanol blend. It contributes to the reduction of gasoline use.

• Tinctures and medical syrups are made with ethyl alcohol.

• It's found in alcoholic drinks.

• It's a solvent for paints, varnishes, and dyes, among other things.

• It's used to make a variety of organic chemicals.

Effect of Alcohol on Human Beings:

Alcohol is a chemical word that refers to a group of organic molecules that include the -OH group. However, the term "alcohol" as used by the public refers to ethyl alcohol or ethanol. It has a wide range of applications, particularly as a solvent. But alcoholic beverages, such as wine, beer, rum, brandy, and whiskey, are by far the most popular way to consume alcohol. It can be used as a source of energy in tiny doses, but in big levels, it can harm the nervous system. The individual loses muscle control, as well as his or her sense of balance and mental abilities. It has the potential to become a habit-forming exercise. Alcohol, when consumed over a long period of time, can be harmful to one's health, particularly the liver, which is prone to cirrhosis. This form of intake is potentially lethal and can destroy a person's family life.

Methylated Spirit or Denatured Alcohol:

The government levies a high tariff on alcoholic beverages to deter people from overindulging. Alcohol used in the industrial and surgical fields is not significantly taxed. However, it is required that ethyl alcohol be blended with a specified percentage of potentially deadly methyl alcohol or methanol to prevent people from buying and consuming this alcohol. As a result, ethyl alcohol is no longer appropriate for human consumption. "Methylated Spirit" is the name given to this combo. Denatured alcohol is ethyl alcohol that has had compounds like copper sulphate or pyridine added to it.

Remember

To prevent people from drinking a lot of ethanol, denatured spirit or methylated spirit mixture is made.

Spurious Alcohol:

This is a type of illegal liquor created through poor distillation or the use of methylated spirit. It is inexpensive and is primarily used by our society's poorer classes. It has a higher concentration of the toxic methyl alcohol. Consumption of such alcoholic beverages might result in blindness, other major health issues, and even death. Other compounds are sometimes added with ethyl alcohol to give the customer an "intoxicating" experience. Even these are extremely dangerous and can cause serious harm to the body, including death.

Ethanoic Acid:

Acetic acid is one of the most prevalent organic acids, and it has been used in the form of vinegar for a long time. It's also found in a variety of fruit juices for free. Many oils and essential oils contain it in its mixed state.

Formula - \[{\text{C}}{{\text{H}}_3}{\text{COOH}}\]

IUPAC Name- Ethanoic acid

At room temperature, acetic acid is a colourless, caustic liquid with a distinct odour. It forms into an icy mass known as glacial acetic acid below 290K. It boils at 391 degrees Fahrenheit and has a specific gravity of 1.08 at 273 degrees Fahrenheit. It is miscible in all ratios with water, alcohol, and ether. Phosphorus, sulphur, iodine, and inorganic substances dissolve well in it. Because it comprises both an alkyl group and an acid moiety (each of the two portions into which a substance is divided), acetic acid possesses the qualities of both groups.

Reactions of Alkyl Group – Halogenation:

Halogen atoms replace the three hydrogen atoms of the alkyl group in acetic acid.

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Reactions Involving Replaceable Hydrogen Atom:

In polar media, acetic acid ionises to produce hydrogen ions, which are responsible for its acidic properties.

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Acetic acid, as a result, can react with alkalis, alkali metal carbonates, and metals.

With Alkalis, Carbonates and Bicarbonates:

Acetic acid changes the colour of blue litmus to red and neutralises alkalis, resulting in the formation of salt and water. Effervescence indicates that it decomposes carbonates and bicarbonates to liberate carbon dioxide.

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The bicarbonate test is used to determine whether a chemical contains a carboxylic group.

With Metals:

Acetic acid forms acetate and liberates hydrogen when it reacts with strongly electropositive metals like sodium and zinc.

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With Alcohols:

In the presence of dehydrating agents such as anhydrous zinc chloride or concentrated sulphuric acid, acetic acid interacts with alcohols to create esters

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Reactions Involving Carboxyl Group as a Whole:

Methane is produced by dry distilling the anhydrous alkali salts of acetic acid with soda-lime.

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Reduction:

Even though acetic acid is resistant to reduction, ethane is produced by heating it under pressure with copious hydriodic acid and red phosphorus. This can also be accomplished by heating the acid with hydrogen at high temperatures and pressures while using a nickel catalyst.

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Acetic acid can be converted to ethanol in the presence of lithium aluminium hydride. The same result is obtained by hydrogenation in the presence of ruthenium or copper-chromium oxide catalysts.

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Oxidation:

Acetic acid is oxidised to carbon dioxide and water when heated for a long time with a strong oxidising agent.

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Uses:

• Ethanoic aid is used in dyes, fragrances, and rayon production.

• Rubber and casein production from latex and milk. It aids in the coagulation of blood.

• In medicine and paints in the form of salts.

• Mordants are utilised in the form of aluminium and chromium acetates.

• When dilute, it's used as vinegar, and when concentrated, it's utilised as a solvent.

• As scents in the form of organic esters.

Soaps & Detergents:

Introduction:

Soaps and detergents are cleansing chemicals that react with water to remove foreign particles from a solid surface (e.g., cloth or skin). Soaps are made from of oils and fats found in animals and plants, while synthetic detergents are made up of mineral oils (hydrocarbon compounds of petroleum or coal). Soaps are sodium or potassium salts of higher fatty acids such as stearic, palmitic, and oleic acids, which can be saturated or unsaturated chemically. They have a lengthy hydrocarbon chain with a functional group of one carboxylic acid. Saturated fatty acids, such as stearic and palmitic, have only single bonds in their molecules, whereas unsaturated fatty acids, such as oleic and linoleic, have one or more double bonds in their molecules. As a result, soaps are often made up of sodium salts of the following acids:

• Saturated fatty acid stearic acid \[({{\text{C}}_{17}}{{\text{H}}_{35}}{\text{COONa)}}\]derived from vegetable oils such as linseed oil and soyabean oil.

• Saturated fatty acid palmitic acid as sodium palmitate \[({{\text{C}}_{17}}{{\text{H}}_{31}}{\text{COONa)}}\]; palm oil, animal fat

• Unsaturated fatty acid oleic acid as sodium oleate \[({{\text{C}}_{17}}{{\text{H}}_{33}}{\text{COONa)}}\]; vegetable oils such as linseed oil and soyabean oil.

When soap is manufactured from the sodium salts of the acids of inexpensive oils or fats, the outcome is a hard soap. These soaps, which include free alkalis, are mostly used as laundry washing bars. Soft soap is produced by combining the potassium salts of the acids found in high-quality oils and fats. There are no free alkalis in these soaps. They are primarily used as toilet soaps, shaving creams, and shampoos because they produce greater lather.

Cleansing Action of Soap:

A soap molecule is fashioned like a tadpole, with oppositely polarised ends. The lengthy hydrocarbon chain at one end is non-polar and hydrophobic, meaning it is insoluble in water but soluble in oil. The short polar carboxylate ion, on the other hand, is hydrophilic, i.e., water-soluble but insoluble in oil and grease.

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When soap is mixed with water and agitated, it forms a colloidal soap solution. Agitating it generates foaming by concentrating the solution on the surface. This assists the soap molecules in forming a unimolecular layer on the water's surface and penetrating the fabric. The hydrophobic extended non-polar end of a soap molecule gravitates towards and surrounds dirt (fat or oil with dust absorbed in it). Face the water away from the dirt with the short polar end carrying the carboxylate ion. In a clustered structure called'micelles,' several soap molecules surround or enclose dirt and oil particles, emulsifying them.

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The dirt and grease are then dislodged from the fabric by the mechanical action of rubbing or tumbling. These are dislodged and washed away with the excess water, leaving the fabric clean.

Limitations of Soaps:

• Soaps do not lather or froth properly in hard water and do not wash well. Hard water's calcium, magnesium, or iron ions generate scum, an intractable sticky grey-colored precipitate that limits soap's cleansing effect and makes washing more difficult. The scum formed also hardens and discolours the fabric. As a result, a lot of soap is wasted, and cleaning is ineffective.

• Why Ordinary soaps are unsuitable for materials like silks and wool. The alkalis in them wreak havoc on the fibre. Soaps cannot be used to clean if the water is slightly acidic in nature. Soaps are converted to carboxylic acid in acid media, rendering their action useless. To address these issues, new chemical-based washing agents have been created. Synthetic detergents, or simply detergents, are what they're called.

Synthetic Detergents:

A detergent is a non-soapy cleaning agent that cleans a substance in solution by using a surface-active ingredient. Soapless soaps are a term used to describe synthetic detergents. They are effective even in hard or salt water, unlike soaps, because they do not develop scum. Alkyl or aryl sulphonates are modern synthetic detergents made from petroleum (or coal) and sulphuric acid. They're defined as "the sodium or potassium salt of a long chain alkyl benzene sulphonic acid that has washing characteristics in water," or "the sodium or potassium salt of a long chain alkyl hydrogen sulphate that has cleansing properties in water."

Detergents, like soaps, include one large non-polar hydrocarbon group and one short ionic or highly polar group at each end, allowing filth to be cleansed in water. The following are two fundamental examples of well-known sulphonate or sulphate detergents:

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Cleansing Action of Detergents:

Synthetic detergents have the same molecular structure as soaps, i.e., a tadpole-like molecule with two components at each end, one big non-polar hydrocarbon group that repels water (hydrophobic) and one short ionic group that attracts water (hydrophilic) (hydrophilic). As a result, the cleansing action is identical to that of soaps, which involves the creation of micelles followed by emulsification.

Synthetic detergents, on the other hand, can lather nicely even in hard water. This is because they are soluble sodium or potassium salts of sulphonic acid or alkyl hydrogen sulphate, and when they react with calcium or magnesium ions in water, they generate soluble calcium or magnesium salts. This is a significant advantage of detergents over soap when it comes to cleaning.

Advantages of Detergents:

• Even in hard water and salt water (sea water), synthetic detergents clean effectively and lather well. 

• Because detergents are the salts of strong acids, they do not break down in an acidic environment. As a result, even if the water is acidic, detergents can efficiently clean the fabric.

• Synthetic detergents are more water soluble than soaps and have a more powerful cleansing activity. Because detergents are made from petroleum, they use less natural vegetable oil, which is an important cooking medium.

Disadvantages of Detergents:

Detergents are surface-active compounds that contribute to a wide range of water pollution issues.

• Many detergents are not biodegradable because they are resistant to the action of biological agents. It is difficult to remove them from municipal wastewaters using standard treatment methods.

• They have a proclivity for forming stable foams in rivers that reach hundreds of metres into the water. Because of the impact of the surfactants used in their manufacture, this is the case. As a result, they endanger aquatic life.

• Because they form a sort of envelope around organic molecules in wastewaters, they tend to limit oxidation.

Differences between Soaps and Detergents

When a straight-chain hydrocarbon is used in place of a branched-chain hydrocarbon in a detergent, the detergent becomes biodegradable. As a result, the most significant disadvantage of detergents can be eliminated.

5 Important Topics of Class 10 Science Chapter 4 You Shouldn’t Miss!

Importance of Science Chapter 4 Notes Carbon and Its Compounds Class 10 PDF

• Learning about carbon and its compounds helps you understand basic organic chemistry. Carbon is important in many everyday things like fuels and plastics.

• This chapter covers how carbon bonds with other elements, which is key to understanding different types of organic compounds.

• Knowing how carbon compounds react and their properties can help you see their uses in real life, such as in making products and energy sources.

• Understanding this chapter can make it easier to solve complex questions and problems in your exams.

• These concepts are important for further studies in chemistry and other related subjects.

Tips For Learning the Class 10 Science Chapter 4 Carbon and Its Compounds

• Focus on how carbon forms four bonds, creating various structures like chains and rings, which is key to understanding organic molecules' shapes and properties.

• Learn the names, structures, and uses of important carbon compounds such as methane, ethene, and alcohols. Flashcards can help reinforce these details.

• Review the reactions involving carbon compounds, like combustion and addition reactions. Practice balancing these reactions to understand the chemical processes better.

• Draw and label structures of different carbon compounds to help visualise and understand their properties and reactions.

• Practice solving past exam questions related to carbon and its compounds to become familiar with the types of questions you might encounter.

Conclusion

Studying the chapter on Carbon and Its Compounds is crucial because it explains the different forms of carbon and their uses in daily life. This chapter covers types of carbon like graphite and diamond and various carbon compounds, including hydrocarbons. Learning about these helps us understand their role in things like fuels, plastics, and medicines. This chapter also shows how these compounds react and why they are important both in industries and for the environment. By understanding these notes, students improve a strong base for more advanced chemistry topics and their real-world applications.

Chapter-wise Links for Science Class 10 Notes

Important Study Materials for Class 10 Science