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There is only one methylene unit less in the formula of the second member of and the third member of the homologous series of alkenes.

Hydrogen gas (H₂) is evolved when ethanol reacts with sodium.

The transformation of ethanol into ethanoic acid is an oxidation process, in which ethanol accepts oxygen.

1. Ethanoic acid is a colourless liquid with boiling point 118 °C and melting point 17 °C. It has a pungent odour. 

2. Its aqueous solution is acidic and turns blue litmus red. 

3. A 5-8% aqueous solution of acetic acid is used as vinegar. 

4. It is a weak acid.

Various useful components of hydrocarbon such as CNG, LPG, petrol (gasoline), rockel, diesel, engine oil, lubricant, etc. are obtained by separation of crude oil using fractional distillation.

1. Ethanol is a colourless liquid and it is soluble in water in all proportions and has pleasant odour. 

2. The boiling point of ethanol is 78 °C and the freezing point is -114 °C. 

3. It is combustible and burns with a blue flame. 

4. An aqueous solution of ethanol is neutral to litmus paper.

The melting point of pure acetic acid is 17 °C. Therefore, during winter in old countries acetic acid freezes at room temperature itself and looks like ice. Therefore it is named glacial acetic acid.

The length of the carbon chains in carbon compounds is different their chemical properties are very much similar due to the presence of the same functional group in them. The series of compounds formed by joining the same functional group in place of a particular hydrogen atom on the chains having sequentially increasing length is called homologous series. Two adjacent members of the series differ by only one -CH₂– (methylene) unit and their mass differ by 14 units.

The homologous series of straight chain alkanes can be represented by the general formula C_nH_{2n + 2}. 

The members of this series are as follows:

Ethanol is the important commercial solvent. To prevent the misuse of this solvent, it is mixed with the poisonous methanol. Such ethanol is called denatured spirit.

The polymers formed from two or more monomers are called copolymers.

Examples: Poly ethylene terephthalate.

The number of carbon atoms: 1

Parent alkane: Methane

Functional group: -COOH (-oic acid)

If the carbon chain of the compound contains a -COOH group, then change the ending of the parent name, i.e. ‘e’ of methane is replaced by ‘-oic acid’.

Parent suffix: Methanoic acid 

IUPAC name: Methanoic acid

The general formula for the homologous series of alkane is C_nH_{2n + 2}. The value of ‘n’ for the first member of homologous series is 1.

C_nH_2n+2 = C₁H_{2 × 1} + 2 = CH₄

If the number of carbon atoms in the molecular formulae of alkenes is denoted by ‘n’ then the number of hydrogen atoms would be 2n.

(i) A is a saturated hydrocarbon, B is an unsaturated hydrocarbon.

(ii) A = Propane, B = Propene

(iii) The chemical formula of A = C₃H₈ and number of -CH₂ units are 3.

The chemical formula of B = C₃H₆ and number of -CH₂ unit is 1.

i. The property of direct bonding between atoms of the same element to form a chain is called catenation.

ii. The molecular weight of two adjacent members in homologous series of an alkane differ by 14 units.

iii. Consecutive members of a homologous series differ by CH₂ group.

iv. Methane is used to prepare carbon black.

v. C_nH_2n is the general formula of alkene.

Straight chain carbon compounds:

1. Propene 

2. Butane.

Branched chain carbon compounds:

1. Iso-butane 

2. Isobutylene.

Ring carbon compounds:

1. Cyclopentane 

2. Benzene.

Open chain hydrocarbons:

1. A hydrocarbon in which the chain of carbon atoms is not cyclic is called an open chain hydrocarbon. 

2. All aliphatic hydrocarbons contain open chains.

Closed chain hydrocarbons:

1. A hydrocarbon in which the chain of carbon atoms is present in a cyclic form or ring form is called a closed chain hydrocarbon. 

2. All aromatic hydrocarbons contain closed chains.

(1) Carbon has a unique ability to form strong covalent bonds with other carbon atoms: this results in formation of big molecules. This property of carbon is called catenation power. The carbon compounds contain open chains or closed chains of carbon atoms. An open chain can be a straight chain or a branched chain. A closed chain is a ring structure. The covalent bond between two carbon atoms is strong and therefore stable. Carbon is bestowed with catenation power due to the strong and stable covalent bonds.

(1) Carbon has a unique ability to form strong covalent bonds with other carbon atoms; this results in formation of big molecules. This property of carbon is called catenation power. The carbon compounds contain open chains or closed chains of carbon atoms. An open chain can be a straight chain or a branched chain. A closed chain is a ring structure. The covalent bond between two carbon atoms is strong and therefore stable. Carbon is bestowed with catenation power due to the strong and stable covalent bonds.

(2) One, two or three covalent bonds can bond together two carbon atoms. These bonds are called single covalent bond, double covalent bond and triple covalent bond respectively. Due to the ability of carbon atoms to form multiple bonds as well as single bonds, the number of carbon compounds increases. For example, there are three compounds, namely, ethane (CH₃ – CH₃), ethene (CH₂ = CH₂) and ethyne (CH = CH) which contain two carbon atoms.

(3) Carbon being tetravalent, one carbon atom can form bonds with four other atoms (carbon or any other). This results in formation of many compounds. These compounds possess different properties as per the atoms to which carbon is bonded. For example, five different compounds are formed using one carbon atom and two monovalent elements hydrogen and chlorine: CH₄, CH₃Cl, CH₂Cl₂, CHCl₃, CCl₄. Similarly carbon atoms form covalent bonds with atoms of elements like O, N, S, halogen and P to form different types of carbon compounds in large number.

(4) Isomerism is one more characteristic of carbon compound which is responsible for large number of carbon compounds.

(1) The molecules of vegetable oil contain long and unsaturated carbon chains. These unsaturated hydrocarbons contain a multiple bond as their functional group. They undergo addition reaction to form a saturated compound as the product.

(2) When vegetable oil (unsaturated compound) is hydrogenated in the presence of nickel catalyst, the addition reaction takes place, vanaspati ghee (saturated compound) is formed.

(1) Vegetable oils (unsaturated compound) contains a multiple bond as their functional group. They undergo addition reaction to form a saturated compound as the product.

(2) The addition reaction of vegetable oil with iodine takes place instantaneously at room temperature. The colour of iodine disappears in this reaction. This iodine test indicates the presence of a multiple bond in vegetable oil.

(1) Teflon 

(2) Styrene 

(3) Alpha aminoacid 

(4) Nucleotide 

(5) R.N.A.

The element carbon belongs to group 14 and its electronic configuration is 2, 4. The valency of carbon is 4.

There are seven electrons in the valence shell of the chlorine.

Answer is Three.

In CO₂, carbon atom is bonded to each of the O atoms by double bond.

Functional groups:

Ether: – O – 

Halogen: – X (-Cl, -Br, -I).

Correct answer is: Teflon.

The nutrients that we get from the foodstuff, namely cereals, pulses and meat are alpha amino acids.

The number of carbon atopic in the longest chain: 4 

Parent alkane: Butane IUPAC name: n-Butane

Saponification: When an ester reacts with the alkali, i.e. sodium hydroxide, the corresponding alcohol and sodium salt of carboxylic acid are obtained. This reaction is called saponification reaction. It is used in the preparation of soap.

Ester + Sodium hydroxide → Sodium salt of carboxylic acid + Alcohol.

The chemical substances that make cloth, furniture and elastic objects are cellulose and rubber.

Organic and inorganic compounds are the two important types of compounds.

Alkyne: The unsaturated hydrocarbons containing a carbon-carbon triple bond are called alkynes.

Example: Ethyne C₂H₂ (CH ≡ CH).

The constituent elements common in these compounds are carbon (C), hydrogen (H) and oxygen (O).

Alkene: The unsaturated hydrocarbons containing a carbon-carbon double bond are called alkenes.

Example : Ethene (CH₂ = CH₂)

Catalyst is a substance, which changes the rate of reaction, without causing any disturbance to it. Vegetable oil (unsaturated compound) undergoes addition reaction with hydrogen in the presence of nickel catalyst to form vanaspati ghee (saturated compound).

Correct answer is: n-butane and i-butane.

The compound acquire specific chemical properties due to these hetero atoms or the groups of atoms that contain hetero atoms, irrespective of length and nature of the carbon chain in that compound. Therefore these hetero atoms or groups of atoms containing hetero atoms are called the functional groups.

Alkane:

1. Alkanes in which the carbon atoms are linked to each other only by single bonds.

2. The general formula of an alkane is C_nH_{2n + 2}

3. They are chemically less reactive.

Alkene:

1. Alkenes in which carbon atoms are linked to each other by double bonds.

2. The general formula of an alkene is C_nH_2n.

3. They are chemically more reactive.

i. The organic compounds having double or triple bonds in them are termed as unsaturated hydrocarbons.

ii. The general formula of alkane is C_nH_{2n + 2}.

iii. The compounds of homologous series have the same functional group.

iv. A double bond is formed between carbon atoms by two pairs of electrons.

v. The compounds having different structural formulae having the same molecular formula is called structural isomerism.

Alkane: In hydrocarbon, the four valencies of carbon atom are satisfied only by the single bonds, such compounds are called alkane. 

Example: Methane (CH₄), Ethane (C₂H₆)

(1) Vinegar is a 5 – 8% aqueous solution of acetic acid. It is used as preservative in pickles. It is used to cook meat. 1t is used as a salad dressing.

(2) To increase the efficiency of petrol, it is mixed with 10% anhydrous ethanol, such a fuel is called gasohol. It is used as a fuel in cars and other vehicles.

Correct answer is: Sodium ethanoate.

International Union of Pure and Applied Chemistry (IUPAC).

The general formula of an alkane is C_nH_{2n + 2}.

Correct answer is: Methane.