Organic Compound

Organic Compound

All compounds of carbon are called organic compounds. Basically organic compounds consist of carbon and hydrogen, these are called hydrocarbons. Some organic compounds also contain oxygen.

1.      Organic compounds are covalent compounds, consist of covalent bonds.

2.      Organic compounds have low melting and boiling points.

3.      Generally they are non-conductors of electricity.

Why Organic compounds have low melting and boiling points?

These are covalent compounds having weak force of attraction between their molecules so they melt and boil at very low temperature.

Why are organic compounds generally non-conductors of electricity?

Since organic compounds are covalent in nature they do not contain ions, so they cannot conduct electricity.

Since Organic compound occur in all living things like plants and animals, earlier it was assumed that these carbon compounds are extracted from the living material be it plant or animal. Hence a “Vital Force Theory” was proposed. According to this theory all organic compounds can only be formed within a living body and hence a vital force that creates the living body was necessary for the formation of these compounds.

This vital force theory was disapproved by a scientist Friedrich Wohler in 1828. Wohler prepared Urea [CO(NH₂)₂], which is an organic compound in laboratory by an inorganic compound called ammonium cyanate (NH₄CNO). Thus it was proved that vital force theory was a misconception.

All carbon compounds are organic compound, but an exception to this is oxides, carbonates, hydrocarbonates and carbides. This is because their properties are very different from the basic organic compounds which are hydrocarbons and their derivatives.

Why a large number of organic compounds are available? 

There are a large number of organic compounds this is because

1.      Carbon atom can link to four other atoms a time, either carbon or other elements forming long chains or rings.

2.      Since the valency is four it can make covalent bond with many different elements like carbon(4), hydrogen(1), oxygen(2), nitrogen(3), sulphur, chlorine(1)

Buckminsterfullerene

Buckminsterfullerene

Buckminsterfullerene is an allotrope of carbon with 60 atoms of carbon joined together forming a hollow spherical structure.

Buckminsterfullerene: properties

1.      Dark, solid

2.      Neither hard nor soft

3.      Weight of buckminsterfullerene is 720.64 g mol

4.      It is a semiconductor

5.      When burned only carbon dioxide is released and no residue is left.

6.      Symbol is C₆₀

Buckminsterfullerene: structure

1.      Cluster of 60 carbon joined together to form small spherical molecule.

2.      Football shaped spherical structure arranged in hexagonal and pentagonal rings of carbon atoms.

3.      Hexagonal and pentagonal rings of carbon atom are interlocked with each other.

4.      One molecule of buckminsterfullerene consists of 20 hexagons and 12 pentagons.

GRAPHITE 

graphite is an allotrope of carbon used as electrode in cells, pencil lead and as lubricant.

Graphite: properties

1.      Greyish black opaque

2.      Soft and slippery to touch

3.      Lighter than diamond

4.      Good conductor of electricity

5.      When burned only carbon dioxide is released and no residue is left.

6.      Symbol is C

Graphite: structure

1.      Graphite crystals consist of layer or sheets of carbon sheet.

2.      Each carbon atom of graphite crystal is joined to three other carbon atoms by strong covalent bonds to form flat hexagonal rings.

3.      The various layer of graphite are quite far from each other so no covalent bonds exist between the layers. So the various layers are held together by Van Der Waals forces.

Why is graphite soft substance?

Since the various layers of carbon atoms in graphite are joined by weak Van Der Waals forces, so the layers can slide over each other. Due to this sheet like arrangement graphite is a soft substance

Why is graphite a good conductor of electricity?

In a graphite crystal each carbon atom is joined to three carbon atoms by covalent bonds. Thus only three electrons are used in bond formation and one electron is left free. This free electron helps in conduction of electricity. Due to presence of electrons graphite crystal conducts electricity.

Uses of graphite

1.      Since graphite is soft, powdered graphite is used as lubricant for fast machinery.

2.      Since graphite is non explosive or non volatile it can be used for lubricating machines that operate at high temperature.

3.      Graphite powder can be used as dry lubricant and when mixed with petro it can be used as graphite grease.

4.      It can be used for making carbon or graphite electrodes in dry cell and electric arcs.

5.      Carbon brushes of electric motor are made of graphite, because it is a good conductor of electricity.

6.      Graphite is used for making the cores of our pencils because of its soft nature.

Diamond

DIAMOND                                                                           

Diamond is an allotrope of carbon generally known for its use in jewellery.

Diamond: properties

1.      Transparent, colourless, Shiny, gleaming and has extreme brilliance

2.      Hard (hardest natural substance)

3.      Very heavy

4.      Does not conduct electricity

5.      When burned only carbon dioxide is released and no residue is left.

6.      Symbol is C

Diamond : structure

1.      Diamond crystal is a big molecule of carbon atoms

2.      Each carbon atom of a diamond crystal is arranged in form of regular tetrahedron, this is a tetrahedral arrangement of atoms.

Why is diamond very hard in nature?

Diamond crystals are made of carbon atom bonded by one another by a network of covalent bond making it very rigid. The rigid structure of diamond makes it a hard substance.

Why is the melting point of diamond very high (3500^o C)?

Lot of heat energy is required to bread the strong network of covalent bondin the diamond crystal.

Why is diamond a non conductor of electricity?

Carbon has 4 valence electrons, in diamond all the 4 valence electrons are engaged in making covalent bond. So, there are no free electrons left. Since there are no free electrons so it does not conduct electricity.

Why diamond shows extreme shine?

Diamond has an ability to reflect and refract light due to this diamond shows brilliance.

Uses of diamond

1.      Since diamond is extremely hard, it is used for cutting and grinding other hard matter. It is used in cutting instrument like glass cutter and rock drilling equipment.

2.      Diamond dies are used for drawing thin wires like tungsten filament of electric bulb

3.      Due to its shine it is used in jewelleries

4.      Sharp edge diamond are used by eye surgeon as tool to remove cataract

Synthetic diamond

Synthetic diamonds are diamond formed artificially. When pure carbon is subjected to high pressure and temperature diamond can be formed artificially.

Carbon and its compounds

Class X

Carbon and its compounds

Carbon is an element. It is a non-metal. All living thing, plant and animal are made up of carbon. These compounds made up of carbon are called organic compound. From The food substance we eat to the fibre we use all are carbon compounds. The fuels like LPG, kerosene, CNG, coal, petrol all are carbon compound. The various substances surrounding us are made up of carbon like wood, paper, rubber, plastic. So, it is a fact that we are surrounded by carbon and its compound.

Atomic number of carbon is 6. The number of electrons in carbon is 6. There are 2 electrons in the K shell of carbon atom. K shell is the innermost shell of an atom. The remaining 4 electrons are in the outer L shell.

Properties of carbon:

1.      Carbon is tetravalent

2.      Carbon form covalent bond

3.      Carbon posses the property of catenation

4.      Carbon burn in air to give carbon dioxide

Tetravalency: The outermost shell of a carbon atom contains 4 electrons. To gain inert gas configuration a carbon atom has to gain four electrons or it has to lose four electrons. Therefore the valency of carbon is 4 and it is called tetravalent.

Covalent bond: due to the tetravalent nature of carbon it is difficult to either remove 4 electrons or to add 4 electrons. Therefore it is obvious that to gain inert gain configuration carbon atom has to share 4 electrons. Since carbon always gain 8-electron configuration by sharing it forms covalent bond.

Catenation: property of carbon to form strong bonds by carbon atoms among themselves and with other elements is called catenation.

Carbon give carbon dioxide on burning: when carbon combines with oxygen it makes carbon dioxide.

Question: why carbon atoms form strong covalent bond?

The reason for formation of strong covalent bonds is the small size of carbon atoms. Due to small size, the nuclei hold the shared electrons for bond strongly, leading to formation of strong covalent bonds. Due to strong bonds these carbon compound they are very stable compounds.

Occurrence of carbon

Carbon occurs in nature in basically two forms:

Elemental form and combined form

Elemental form: the form in which carbon occur in free state that means elemental state. Diamond, graphite and buckminsterfullerene are the three forms that are available in nature

Combined form: carbon occurs in nature in form of compound. When carbon combine with oxygen, hydrogen and other elements present in nature then these are called carbon compound and this is the combined form of carbon. Example are CNG, petrol, coal, wood, carbonates, marble, cotton, grains etc.

Allotropy

The phenomenon in which an element exists in more than one physical form in nature is called allotropy. The various physical forms in which the element is available are called allotropes.

Allotropes of carbon are diamond, graphite, buckminsterfullerene, charcoal(amorphous).

Next Topic Diamond

SOLUTION MCQ Carbond and its compounds

Class X     QUESTIONS

SOLUTION MCQ Carbond and its compounds

1.Correct answer: c

Explanation: buckminsterfullerene is an allotrope of carbon containing cluster of 60 carbon atom joined together to form spherical molecule.

2.Correct answer: a

Explanation: atomic number of carbon is 6. Maximum number of electrons in K energy shell is 2 and remaining 4 electrons in L shell. Therefore the electronic configuration of carbon is  K2, L4

3.correct answer: d

explanation: saturated hydrocarbon are those hydrocarbon in which two carbon are connected with a single bond. unsaturated hydrocarbons are those hydrocarbon that are connected by a double bond or a triple bond

4. correct answer: b

explanation: outermost shell of a carbon atom has 4 electrons. It is not possible to add or to remove 4 electrons from an carbon atom. Due to its configuration carbon atom can achieve inert gas configuration only by sharing its electrons, so carbon always form covalent bonds.

5.correct answer: c

explanation: diamond has no free electrons to conduct electricity

6.correct  answer: a

explanation: graphite is soft because of its sheet like arrangement

7.correct answer: a

explanation: it is a dark solid in room temparature

8.correct answer: b

explanation: two carbon is indicated by eth. Examples are ethane, ethane.

9.correct answer: c

explanation: organic compound having same molecular formula but different structures are called isomers.

10.Correct answer: c

explanation: CH_4, C₂H_{6 ,} C₄H₁₀  are alkanes whereas  C₂H₄ is an alkene

11.correct answer:d

explanation: one carbon atom require 4 electron for sharing and gaining inert pair configuration. So its valency is 4. This means carbon is tetravalent

12.correct answer:b

explanation: the property of carbon to form strong bonds among themselves is called catenation.

13.correct answer: a

explanation: carbonate, wood and carbohydrate are carbon in combined form. Free state of carbon is the form when carbon occur as element,

14.correct answer: b

explanation: buckminsterfullerene and diamond are carbon in elemental form. Carbonates are carbon in combination with oxygen

15.correct answer: b

explanation: diamond, graphite, buckminsterfullerene are pure form of carbon

MCQ Carbon and compounds

Class X

Carbon and compounds

multiple choice questions

1. which of following is buckminsterfullerene

a. C₄₀

b. C₅₀

c. C₆₀

d. C₇₀

2. Electronic configuration of carbon is

a. K2, L4

b. K1, L5

c. K2, L5

d. K1, L4

3. what are unsaturated hydrocarbons?

a. carbon atoms connected by single bond

b. carbon atoms connected by double bond

c. carbon atoms connected by triple bond

d. b and c

4.  Which type of bond does carbon form

a. ionic

b. covalent

c. both ionic and covalent bond

d. carbon makes a different type of bond

5 . which one is not a property of diamond

a. it is  hard

b. conducts electricity

c. does not conduct electricity

d. burns to form carbon dioxide

6 . why is graphite a soft substance

a. because of its sheet like structure

b. because it is made of carbon

c. because of its spherical arrangement of atoms

d. because it has free electrons

7. in which state is buckminsterfullerene found in room temprature  

a. solid

b.liquid

c.gas

d. plasma

8. two carbon is indicated by

a. prop

b. eth

c. meth

d. but

9.  organic compound having same molecular formula but different structures are called

A .isotopes

b. allotropes

c. isomers

d. isobars

10. which one is not in homologous series:

a. CH₄

b. C₂H₆

c. C₂H₄

d. C₄H₁₀

11. what kind of atom is carbon

a. monovalent

b. divalent

c. trivalent

d. tetravalent

12. What is the meaning of catenation?

a. tetravalency

b. self combination

c. formation of ionic bonds

d. formation of covalent bonds

13. which one is carbon occurring in free state.

a. diamond

b. carbonate

c.wood

d. carbohydrates

14 . which form of carbon is in combined state?

a. buckminsterfullerene

b.  carbonate

c. diamond

d. a and b

15 . which one is not an allotrope of carbon

a. diamond

b .silicon

c. graphite

d. buckminsterfullerene

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