Carbon and its Compounds

What are Carbon and its Compounds?

The molecules of a carbon compound must contain an atom of carbon. All living things, including plants and animals, are composed of organic components, which are carbon-based substances.

Carbon compounds are present everywhere i.e. in the food that we eat, the clothes that we wear and even in the lead of the pencil by which we write. The atomic number of carbon is 6 and the atomic mass is 12.01gmol-1. Carbon is a member of the 14th group. According to the data, it is the seventeenth most abundant element found on Earth. It is found in both free as well as in the combined state.

It is found in both free as well as in the combined state. It can be available as coal, graphite in the elemental state. Whereas it is present as metal carbonates, hydrocarbons, and carbon dioxide gas in the combined state. When it combines with other elements such as dihydrogen, dioxygen, chlorine, and sulphur provides amazing arrays of materials that can vary from tissues to medicines.

Chemical Properties of Carbon

Group	14	Melting point	Sublimes at 3825°C, 6917°F, 4098 K
Period	2	Boiling point	Sublimes at 3825°C, 6917°F, 4098 K
Block	p	Density (g cm−3)	3.513 (diamond); 2.2 (graphite)
Atomic number	6	Relative atomic mass	12.011
State at 20°C	Solid	Key isotopes	294Ts
Electron configuration	[He]2s2 2p2	CAS number	87658-56-8
ChemSpider ID	–	ChemSpider is a free chemical structure

What is Carbon?

• Carbon is an element represented by C, it belongs to the 14th period in the periodic table.
• The atomic number of carbon is 6 and the atomic mass is 12.01gmol-1.
• Carbon is a nonmetal and tetravalent i.e has 4 electrons in the valence shell.
• According to the data, it is the seventeenth most abundant element found on earth. It is found in the minerals of most metals in the form of carbonates. 
• Carbon is the 2nd most abundant element in the human body.

Existence of Carbon

• Carbon has three naturally occurring isotopes namely C-12, C-13 and C-14. C-12 is the most abundant whereas C-14 is radioactive and used for carbon dating.
• Atomic carbon is short-lived but it is stabilised by allotropic forms. Carbon has three allotropes namely diamond, graphite and amorphous form. The properties of these allotropes are different due to the different arrangements of C atoms inside them. 
• The most common oxidation state of carbon is +4. It can also form +2 and 0 oxidation states in inorganic compounds and carbonyls.

Properties of Carbon

• The electronic configuration of C is 1s2 2s2 2p2. So it is tetravalent and can form four covalent bonds.
• Catenation is the special feature of carbon by which it can form long-chain compounds. C-C bonds are non-polar and stronger. 
• Carbon products are obtained by heating coal, natural gas or wood or bone at elevated temperatures in the presence of insufficient oxygen to allow combustion. 
• Carbon reacts with oxygen to form carbon oxides at elevated temperatures and can steal oxygen from metal oxides to leave only the elemental metal.
• Most forms of carbon are comparatively unreactive.
• Most of the fuel is made up of carbon and its compounds. When carbon burns in the presence of oxygen, it produces heat and light. This process of burning carbon and its compounds to release energy is known as combustion.
• Carbon mainly takes part in the four main types of reaction such as oxidation reactions, addition reactions, substitution reactions and combustion reactions.

Catenation Property of Carbon

In Organic Chemistry, everything is surrounded by carbon compounds. It is one of the most essential components of living organisms. There are two stable isotopes of carbon 12C and 13C. After these two one more isotope of carbon is present 14C. Carbon is used for radiocarbon dating and it is also a radioisotope with a half-life of 5770 years.

• One of the most amazing properties of carbon is its ability to make long carbon chains and rings. This property of carbon is known as catenation.
• Carbon has many special abilities out of all one unique ability is that carbon forms pπ-pπ bonds which are nothing but double or triple bonds with itself and with other electronegative atoms like oxygen and nitrogen.
• Just because of these two properties of carbon i.e catenation and multiple bond formation, it has the number of allotropic forms.
• Carbon atoms form tetravalent bonds , so that one carbon atom forms a bond  with four carbon atoms and this structure can be repeated endlessly without disturbing the stability of the bonds.

 

Do you know what the allotrope of carbon means?

Allotrope is nothing but the existence of an element in many forms which will have different physical properties but will have similar chemical properties and its forms are called allotropes of allotropic forms. Allotropes are defined as the two or more physical forms of one element. These allotropes are all based on carbon atoms but exhibit different physical properties, especially with regard to hardness.

The common, crystalline allotropes of carbon are Diamond, Graphite, Graphene, Fullerene ( C60), and Carbon nanotubes. Carbon shows allotropy because it exists in different forms of carbon such as diamond, and graphite. But it is now known that all the amorphous carbons contain microcrystals of graphite. Though these allotropes of carbon have different crystal structures and different physical properties, their chemical properties are the same and show similar chemical properties. Both diamond and graphite have the symbol C. Both give off carbon dioxide when strongly heated in the presence of oxygen.

The structure of carbon allotropes are 

Diamond:  

Diamond is a  well known allotrope of carbon having a three-dimensional network  structure. It exhibits the highest hardness and thermal conductivity. 

Graphite:

Graphite is another allotrope of carbon. It is a two dimensional structure and a good conductor of electricity.

Graphene:

It is a single layer allotrope of carbon having a two dimensional honeycomb structure. Graphene has very high electron mobility and, like graphite, is a good electrical conductor, due to the occurrence of a free pi (p) electron for each carbon atom.

Fullerene (C6O):

A fullerene is an allotrope of carbon atoms connected by single and double bonds to form a closed or partially closed structure, with fused rings of five to seven atoms.

Single-wall carbon nanotubes:

Single-wall carbon nanotubes are one of the allotropes of carbon, intermediate between fullerene cages and flat graphene.

 

Types of Carbon Compounds

1. Saturated Carbon Compounds

These are the compounds in which various carbon atoms in a chain or a ring are linked together by single bonds only. Alkanes are the most common examples of saturated chain carbon compounds. Ethane is a member of the alkane family whose structure is drawn below:

2. Unsaturated Carbon Compounds

These are the compounds in which various carbon atoms in a chain or a ring are linked together by double or triple bonds. Alkenes (where carbon atoms are linked through double bonds) and alkynes (where carbon atoms are linked through triple bonds) are the most common examples of unsaturated chain carbon compounds. Ethene is a member of the alkene family whose structure is drawn below:

Catenation Property of Carbon

• One of the most amazing properties of carbon is its ability to make long carbon chains and rings. This property of carbon is known as catenation.
• Carbon has many special abilities out of all one unique ability is that carbon forms pπ-pπ bonds which are nothing but double or triple bonds with itself and with other electronegative atoms like oxygen and nitrogen.
• Just because of these two properties of carbon i.e catenation and multiple bond formation, it has the number of allotropic forms.

The Existence of Carbon Compounds

Carbon is one of the more widespread heavy elements – it may make up almost 0.5 percent of the universe mass. The solar system formed from a material that was quite rich in carbon. Even then the element only makes up 0.025 percent of Earth’s crust and most of this carbon bound up in rocks and minerals such as limestone and chalk. But carbon is highly concentrated in living creatures and accounts for nearly one-quarter of atoms in our tissues.

The carbon compounds exist mainly in three ways:

1. Straight Chains

In such kind of arrangement one carbon atom is bonded to another carbon forming a straight line without developing any branches. Low molecular weight hydrocarbons exist in straight chains. For example ethane

2. Branches

Carbon compounds with higher molecular weight mostly exist in branched form i.e. one of the carbon atoms is bonded to more than two carbon atoms. For example isopentane.

3. Rings

In this kind of arrangement, three or more carbon atoms are linked together in such a way that they form closed cycles. Such compounds are also known as cyclic compounds. For example, cyclohexane.

Some Carbon based compounds

Carbon -hydrogen compounds:

Hydrocarbons are the compound of carbon having a carbon hydrogen bond. Such as CH4, C2H6, C2H4, C6H6 etc. 

Carbon-oxygen compounds:

There are many oxides of carbon compounds there such as carbon dioxide (CO2), carbon monoxide (CO), carbon trioxide (CO3) etc.

Carbon-sulfur compounds:

The carbon-sulphide compounds are carbon disulphide (CS2) and carbonyl sulphide (OCS). Carbon monosulphide (CS) etc.

Carbon-nitrogen compounds

The carbon-nitrogen compounds are cyanogen (CN)2 , hydrogen cyanide (HCN), cyanogen chloride (CNCl) etc.

Carbon- halides compounds

The common carbon halides are carbon tetrafluoride (CF4), carbon tetrachloride (CCl4), carbon tetrabromide (CBr4), carbon tetraiodide (CI4) etc

Uses of Carbon

• One of the most amazing properties of carbon is its ability to make long carbon chains and rings. This property of carbon is known as catenation.
• Carbon has many special abilities amongst one unique ability is that carbon forms pπ-pπ bonds which are nothing but double or triple bonds with itself and with other electronegative atoms like oxygen and nitrogen.
• Just because of these two properties of carbon i.e catenation and multiple bond formation, it has a number of allotropic forms.Uses of carbon and its compounds

• Carbon is the basic building block of life.
• Hydrocarbons are the compounds of carbon and hydrogen are the major source of fuel.
• Carbon based compounds like ethylene, polypropene, polystyrene etc. are widely used in polymerisation process.
• They are used in the synthesis of many dyes and drugs.
• Diamond is a allotrope of carbon used for cutting marble, granite and glass, it is also used for jewellery.
• Graphite  is used to make electrodes for electrolytic cells, for making pencils, lubricates for machines.
• Glucose  is made of carbon , hydrogen and oxygen used is the main source of fuel for our cells.

Covalent Bonding

Difficulty of Carbon to Form a Stable Ion

To achieve the electronic configuration of the nearest noble gas, He, if the carbon atom loses four of its valence electrons, a huge amount of energy is involved. C4+ ion hence formed, will be highly unstable due to the presence of six protons and two electrons.

If the carbon atom gains four electrons to achieve the nearest electronic configuration of the noble gas, Ne, C4− ion will be formed. But again, a huge amount of energy is required. Moreover, in C4+ ions it is difficult for 6 protons to hold 10 electrons. Hence, to satisfy its tetravalency, carbon shares all four of its valence electrons and forms covalent bonds.

Ionic Bond

Ionic bonding involves the transfer of valence electron/s, primarily between a metal and a nonmetal. The electrostatic attractions between the oppositely charged ions hold the compound together.
Ionic compounds:

1. Are usually crystalline solids (made of ions)
2. Have high melting and boiling points
3. Conduct electricity when melted
4. Are mostly soluble in water and polar solvents

Covalent Bond

A covalent bond is formed when pairs of electrons are shared between two atoms. It is primarily formed between two same nonmetallic atoms or between nonmetallic atoms with similar electronegativity.

Lewis Dot Structure

Lewis structures are also known as Lewis dot structures or electron dot structures.
These are basically diagrams with the element’s symbol in the centre. The dots around it represent the valence electrons of the element.

Lewis structures of elements with atomic numbers 5-8

Covalent Bonding in H2, N2 and O2

Formation of a single bond in a hydrogen molecule:
Each hydrogen atom has a single electron in the valence shell. It requires one more to acquire the nearest noble gas configuration (He).
Therefore, both the atoms share one electron each and form a single bond.

 

Formation of a double bond in an oxygen molecule:
Each oxygen atom has six electrons in the valence shell (2, 6). It requires two electrons to acquire the nearest noble gas configuration (Ne).
Therefore, both the atoms share two electrons each and form a double bond.

 

Formation of a triple bond in a nitrogen molecule:
Each nitrogen atom has five electrons in the valence shell (2, 5). It requires three electrons to acquire the nearest noble gas configuration (Ne).
Therefore, both atoms share three electrons each and form a triple bond.

Single, Double and Triple Bonds and Their Strengths

A single bond is formed between two atoms when two electrons are shared between them, i.e., one electron from each participating atom.
It is depicted by a single line between the two atoms.

A double bond is formed between two atoms when four electrons are shared between them, i.e., one pair of electrons from each participating atom. It is depicted by double lines between the two atoms.

A triple bond is formed between two atoms when six electrons are shared between them, i.e., two pairs of electrons from each participating atom. It is depicted by triple lines between the two atoms.

Bond strength:
– The bond strength of a bond is determined by the amount of energy required to break a bond.
– The order of bond strengths when it comes to multiple bonds is: Triple bond>double bond>single bond
– This is to signify that the energy required to break three bonds is higher than that for two bonds or a single bond.

Bond length:
– Bond length is determined by the distance between nuclei of the two atoms in a bond.
– The order of bond length for multiple bonds is: Triple bond<double bond<single bond
The distance between the nuclei of two atoms is least when they are triple bonded.

Covalent Bonding of N, O with H and Polarity

In ammonia $\left(N{H}_3\right)$, the three hydrogen atoms share one electron each with the nitrogen atom and form three covalent bonds.

 

• Ammonia has one lone pair.
• All three N-H covalent bonds are polar in nature.
• N atom is more electronegative than the H atom. Thus, the shared pair of electrons lies more towards N atom.
• This causes the N atom to acquire a slight negative charge and H atom a slight positive charge.

 

In water (H2O), the two hydrogen atoms share one electron each with the oxygen atom and form two covalent bonds.

 

• Water has two lone pairs. ​
• The two O-H covalent bonds are polar in nature.
• The ​​​​​​O atom is more electronegative than the H atom. Thus, the shared pair of electrons lies more towards O atom.
• This causes the O atom to acquire a slight negative charge and H atom a slight positive charge.

​​​​​​​​​​​​​​​​​​​​​​​​​

Covalent Bonding in Carbon

A methane molecule (CH4) is formed when four electrons of carbon are shared with four hydrogen atoms, as shown below.

Why Carbon Can Form so Many Compounds

Catenation occurs most readily with carbon due to its small size, electronic configuration and unique strength of carbon-carbon bonds. Tetravalency, catenation, and the tendency to form multiple bonds with other atoms account for the formation of innumerable carbon compounds.

Catenation

Catenation is the self-linking property of an element by which an atom forms covalent bonds with the other atoms of the same element to form straight or branched chains and rings of different sizes. It is shown by carbon, sulphur and silicon.

S8

In its native state, sulphur shows catenation of up to 8 atoms in the form of S8 molecule. It has a puckered ring structure.

Versatile Nature of Carbon

Tetravalency and Catenation The fact that carbon can form single, double, and triple bonds demonstrate its versatility. It can also form chains, branching chains, and rings when joined to other carbon atoms.

Hydrogen, oxygen, carbon, and a few additional elements make up organic molecules. Organic compounds, on the other hand, are significantly more numerous than inorganic compounds that do not form bonds.

Carbon is a chemical element with the atomic number 6 and the symbol C. It’s a versatile element that can be found in a wide variety of chemical combinations. Carbon’s versatility is best appreciated through properties like tetravalency and catenation.

• Tetravalency: Carbon has a valency of four, so it is capable of bonding with four other atoms of carbon or atoms of some other mono-valent element.
• Catenation: The property of a carbon element due to which its atom can join one another to form long carbon chains is called catenation.

Mp, Bp and Electrical Conductivity

Covalent compounds:

1. Are molecular compounds
2. Are gases, liquids or solids
3. Have weak intermolecular forces
4. Have low melting and boiling points
5. Are poor electrical conductors in all phases
6. Are mostly soluble in nonpolar liquids

Allotropes of Carbon

– The phenomenon of the existence of the same element in different physical forms with similar chemical properties is known as allotropy.
– Some elements like carbon, sulphur, phosphorus, etc., exhibit this phenomenon.
– Crystalline allotropes of carbon include diamond, graphite and, fullerene.
– Amorphous allotropes of carbon include coal, coke, charcoal, lamp black and gas carbon.

Diamond

Diamond has a regular tetrahedral geometry. This is because each carbon is connected to four neighbouring carbon atoms via single covalent bonds, resulting in a single unit of a crystal. These crystal units lie in different planes and are connected to each other,  resulting in a rigid three-dimensional cubic pattern of the diamond.

Diamond:

1. Has a high density of 3.5g/cc.
2. Has a very high refractive index of 2.5.
3. Is a good conductor of heat.
4. Is a poor conductor of electricity.

Graphite

In graphite, each carbon atom is bonded covalently to three other carbon atoms, leaving each carbon atom with one free valency. This arrangement results in hexagonal rings in a single plane, and such rings are stacked over each other through weak Van der Waals forces.

Graphite:

1. Has a density of 2.25 g/cc.
2. Has a soft and slippery feel.
3. Is a good conductor of electricity.

C60

C60, also known as Buckminsterfullerene, is the very popular and stable form of the known fullerenes.
It is the most common naturally occurring fullerene and can be found in small quantities in soot.
It consists of 60 carbon atoms arranged in 12 pentagons and 20 hexagons, like in a soccer ball.

Chains, Branches and Rings

Saturated and Unsaturated Hydrocarbons

Saturated hydrocarbons: These hydrocarbons have all carbon-carbon single bonds. These are known as alkanes. General formula = CnH2n+2 where n = 1, 2, 3, 4.…..
Unsaturated hydrocarbons: These hydrocarbons have at least one carbon-carbon double or triple bond.
Hydrocarbons with at least one carbon-carbon double bond are called alkenes. General formula = CnH2n where n = 2, 3, 4…..
Hydrocarbons with at least one carbon-carbon triple bond are called alkynes. General formula = CnH2n−2 where n = 2, 3, 4…..

Chains, Rings and Branches

Carbon chains may be in the form of straight chains, branched chains or rings.

 

In cyclic compounds, atoms are connected to form a ring.

 

Structural Isomers

Compounds with the same molecular formula and different physical or chemical properties are known as isomers and the phenomenon is known as isomerism.
The isomers that differ in the structural arrangement of atoms in their molecules are called structural isomers and the phenomenon is known as structural isomerism.

 

Benzene

Benzene is the simplest organic, aromatic hydrocarbon.
Physical properties: colourless liquid, pungent odour, flammable, volatile.
Structure:
Cyclic in nature with chemical formula C6H6, i.e., each carbon atom in benzene is arranged in a six-membered ring and is bonded to only one hydrogen atom.
It includes 3 double bonds, which are separated by a single bond.
Hence, this arrangement is recognized to have conjugated double bonds and two stable resonance structures exist for the ring.

 

Functional Groups and Nomenclature

Functional Groups

An atom or a group of atoms which, when present in a compound, gives specific physical and chemical properties to it regardless of the length and nature of the carbon chain is called a functional group.

Classification of Functional Groups

Main Functional Groups:

(i) Hydroxyl group (-OH): All organic compounds containing -OH group are known as alcohols. For example, Methanol (CH3OH), Ethanol (CH3−CH2−OH), etc.

(ii) Aldehyde group (-CHO): All organic compounds containing -CHO group are known as aldehydes. For example, Methanal (HCHO), Ethanal (CH3CHO), etc.

(iii) Ketone group (-C=O): All organic compounds containing (-C=O) group flanked by two alkyl groups are known as ketones. For example, Propanone (CH3COCH3), Butanone (CH3COCH2CH3), etc.

(iv) Carboxyl group (-COOH): All organic acids contain a carboxyl group (-COOH). Hence, they are also called carboxylic acids.
For example, Ethanoic acid (CH3COOH), Propanoic acid (CH3CH2COOH), etc.

(v) Halogen group (F, CI, Br, I): The alkanes in which one or more than one hydrogen atom is substituted by- X (F, CI, Br or I) are known as haloalkanes. For example, Chloromethane (CH3Cl), Bromomethane (CH3Br), etc.

Homologous Series

Homologous series constitutes organic compounds with the same general formula, and similar chemical characteristics but different physical properties. The adjacent members differ in their molecular formula by −CH2.

Examples of homologous series

Methane, ethane, propane, butane, etc. are all part of the alkane homologous series.
The general formula of this series is CnH2n+2.
Methane (CH4), Ethane (CH3CH3), Propane (CH3CH2CH3), Butane (CH3CH2CH2CH3).
It can be noticed that there is a difference of −CH2 unit between each successive compound.

Nomenclature of Carbon Compounds

The International Union of Pure and Applied Chemistry (IUPAC) decided on some rules for naming carbon compounds. This was done to maintain uniformity throughout the world. Names which are given on this basis are popularly known as IUPAC names.

Physical Properties

The members of any particular family have almost identical chemical properties due to the same functional group. Their physical properties, such as melting point, boiling point, density, etc., show a regular gradation with the increase in molecular mass.

Chemical Properties

A chemical property is a property that describes a substance’s ability to undergo a specific chemical change. We look for a chemical shift to identify a chemical attribute. A chemical change always results in the formation of one or more types of matter that are distinct from the matter that existed before the change.

Combustion Reactions

Combustion means the burning of carbon or carbon-containing compounds in the presence of air or oxygen to produce carbon dioxide, heat and light.

2CH3OH + 3O2 → 4H2O + 2CO2

For example,

Naphthalene also undergoes combustion in the presence of oxygen to afford carbon dioxide gas and water. The chemical equation for this reaction is as follows.

12O2 + C10H8 → 4H2O + 10CO2

Flame Characteristics

Saturated hydrocarbons give a clean flame, while unsaturated hydrocarbons give a smoky flame. In the presence of limited oxygen, even saturated hydrocarbons give smoky flame.

A black substance formed by combustion or separated from fuel during combustion, rising in fine particles and adhering to the sides of the chimney or pipe conveying the smoke especially: the fine powder consisting chiefly of carbon that colours smoke called soot.

Oxidation

Oxidation is a chemical reaction that occurs in an atom or compound and results in the loss of one or more electrons.

Addition

The reactions in which two molecules react to form a single product having all the atoms of the combining molecules are called addition reactions.
The hydrogenation reaction is an example of the addition reaction. In this reaction, hydrogen is added to a double bond or a triple bond in the presence of a catalyst like nickel, palladium or platinum.

 

Substitution

The reaction in which an atom or group of atoms in a molecule is replaced or substituted by different atoms or groups of atoms is called a substitution reaction. In alkanes, hydrogen atoms are replaced by other elements.

CH4+Cl2+Sunlight → CH3Cl+HCl

Ethanol and Ethanoic Acid

Ethanol

(i) Ethanol, C2H5OH is a colourless liquid having a pleasant smell.
(ii)   It boils at 351 K.
(iii)  It is miscible with water in all proportions.
(iv)  It is a nonconductor of electricity (it does not contain ions)
(v)   It is neutral to litmus.

Uses:

1. As an antifreeze in radiators of vehicles in cold countries.
2. As a solvent in the manufacture of paints, dyes, medicines, soaps and synthetic rubber.
3. As a solvent to prepare the tincture of iodine.

How Do Alcohols Affect Human Beings?

(i)      If ethanol is mixed with CH3OH and consumed, it causes serious poisoning and loss of eyesight.
(ii)     It causes addiction, and damages the liver if taken in excess.
(iii)    High consumption of ethanol may even cause death.

Reactions of Ethanol with Sodium

Ethanol reacts with sodium to produce hydrogen gas and sodium ethoxide. This reaction supports the acidic character of ethanol.
2C2H5OH+2Na → 2C2H5ONa+H2(↑)

Elimination Reaction

An elimination reaction is a type of reaction in which two substituents are removed from a molecule. These reactions play an important role in the preparation of alkenes.

Dehydration Reaction

Ethanol reacts with concentrated sulphuric acid at 443 K to produce ethylene. This reaction is known as dehydration of ethanol because, in this reaction, a water molecule is removed from the ethanol molecule.

CH3CH2OH → CH2=CH2+H2O

(reaction taking place in the presence of Conc.H2SO4)

Ethanoic Acid or Acetic Acid

(i)        Molecular formula: CH3COOH
(ii)       It dissolves in water, alcohol and ether.
(iii)      It often freezes during winter in a cold climate, and therefore, it is named glacial acetic acid.

Esterification

When a carboxylic acid is refluxed with alcohol in the presence of a small quantity of conc.H2SO4, a sweet-smelling ester is formed. This reaction of ester formation is called esterification.

When ethanol reacts with ethanoic acid in the presence of conc.H2SO4, ethyl ethanoate and water are formed.
CH3COOH+C2H5OH → CH3COOC2H5+H2O

(reaction taking place in the presence of Conc.H2SO4)

Saponification

A soap is a sodium or potassium salt of long-chain carboxylic acids (fatty acid). The soap molecule is generally represented as RCOONa, where R = non-ionic hydrocarbon group and  −COO−Na+ ionic group. When oil or fat of vegetable or animal origin is treated with a concentrated sodium or potassium hydroxide solution, hydrolysis of fat takes place; soap and glycerol are formed. This alkaline hydrolysis of oils and fats is commonly known as saponification.

Reaction of Ethanoic Acid with Metals and Bases

Ethanoic acid (Acetic acid) reacts with metals like sodium, zinc and magnesium to liberate hydrogen gas.
2CH3COOH+2Na→2CH3COONa+H2(↑)

It reacts with a solution of sodium hydroxide to form sodium ethanoate and water.
CH3COOH+NaOH→CH3COONa+H2O

Reaction of Ethanoic Acid with Carbonates and Bicarbonates

Carboxylic acids react with carbonates and bicarbonates with the evolution of CO2 gas. For example, when ethanoic acid (acetic acid) reacts with sodium carbonate and sodium bicarbonate, CO2 gas is evolved.
2CH3COOH+Na2CO3→2CH3COONa+H2O+CO2
CH3COOH+NaHCO3→CH3COONa+H2O+CO2

Soaps and Detergents

Cleansing Action of Soap

When soap is added to water, the soap molecules uniquely orient themselves to form spherical shape micelles.

The non-polar hydrophobic part or tail of the soap molecules attracts the dirt or oil part of the fabric, while the polar hydrophilic part or head,(−COO−Na+, remains attracted to water molecules.

 

The agitation or scrubbing of the fabric helps the micelles to carry the oil or dirt particles and detach them from the fibres of the fabric.

Hard Water

Hard water contains salts of calcium and magnesium, principally as bicarbonates, chlorides, and sulphates. When soap is added to hard water, calcium and magnesium ions of hard water react with soap forming insoluble curdy white precipitates of calcium and magnesium salts of fatty acids.

2C17H35COONa+MgCl2 → (C17H35COO)2Mg+2NaCl
2C17H35COONa+CaCl2 → (C17H35COO)2Ca+2NaCl

These precipitates stick to the fabric being washed and hence, interfere with the cleaning ability of the soap. Therefore, a lot of soap is wasted if the water is hard.