# NCERT Solutions for Class 10 Science Chapter 4 Carbon and Its Compounds

## Here are the important topics of NCERT Solutions for Class 10 Science Chapter 4 Carbon and Its Compounds mentioned below:

4.1 Bonding in Carbon - The Covalent Bond

4.2 Versatile Nature of Carbon

4.2.1 Saturated and Unsaturated Carbon Compounds

4.2.2 Chains, Branches, and Rings

4.2.4 Homologous Series

4.2.5 Nomenclature of Carbon Compound

4.3 Chemical Properties of Carbon Compounds

4.3.1 Cumbustion

4.3.3 Oxidation

4.3.5 Substitution Reaction

4.4 Some Important Carbon Compounds - Ethanol and Ethanoic Acid

4.4.1 Properties of Ethanol

4.4.2 Properties of Ethanoic Acid

4.5 Soaps and Detergents

## NCERT textbook solutions for class 10 science chapter 4 Carbon and its compounds - Points to remember

• Carbon is a versatile element that forms the large variety of compounds because of carbon tetravalency and the property of catenation that it exhibits.

• The basis for all living organisms and many of the things we use are formed by carbon.

• ## Covalent bonds are formed by the sharing of electrons between two atoms in order that both are able to do a totally filled outermost shell.

• Carbon forms covalent bonds with itself and other elements such as hydrogen, oxygen, sulfur, nitrogen, and chlorine.
• Carbon also forms compounds containing double and triple bonds between carbon atoms. These carbon chains could also be in the form of straight chains, branched chains or rings.
• The ability of carbon to form chains gives rise to a homologous series of compounds during which an equivalent functional group is attached to carbon chains of various lengths.

If you face any problem while solving the NCERT textbook questions then, NCERT Solutions for Class 10  is there for you to help.

## NCERT solutions for class 10 science chapter 4 Carbon and its compounds

Topic:4.1 Bonding in carbon - The covalent bond

The electron dot structure of carbon dioxide which has the formula $CO_{2}$ is:

The electron dot structure of a molecule of $S_8$ is:

## NCERT textbook solutions for class 10 science chapter 4 carbon and its compounds

Topic 4.2: Versatile nature of carbon

There are three structural isomers of pentane:

 n-pentane iso-pentane neo-pentane

The two properties of carbon which lead to the formation of a large number of carbon compounds are:

(1) Catenation: Carbon has the unique ability to form bonds with other atoms of carbon which gives rise to large molecules. The carbon-carbon bond is very strong and hence stable.

(2) Tetravalency: Since carbon has a valency of four, it is capable of bonding with four other atoms. These bonds that carbon forms with other elements are very strong making these compounds exceptionally stable.

The formula of cyclopentane is $C_5H_{10}$.

And, the electron dot structure of cyclopentane is :

The structure of ethanoic acid is:

(ii)  Bromopentane

Are structural isomers possible for bromopentane?

The structure of bromopentane($C_5H_{11}Br$) is:

Yes, structural isomers for bromopentane is possible.

For n-pentane: Br at $2^{nd}\ and\ 3^{rd}$ carbon

Also, Br at different carbons for iso-pentane and neo-pentane.

(iii)  Butanone

The structure of Butanone ($C_2H_5COCH_3$) is:

(iv)  Hexanal

The structure of hexanal ($C_5H_{11}CHO$) is:

$CH_{3}-CH_{2}-Br$

The compound ($CH_{3}-CH_{2}-Br$ ) has 2 carbon atoms. Hence the parent hydrocarbon is ethane.

A bromo group is attached to one of the carbon atoms. Thus, the nomenclature of the compound is Bromoethane.

The compound ($H_2 C = 0$) contains 1 carbon atom. Hence the parent hydrocarbon is methane. It contains the functional group aldehyde.

Thus, the nomenclature of the compound is: Methanal.

The compound has 6 carbons in the chain. Hence the parent hydrocarbon is hexane. It contains a triple bond and hence the suffix -yne- is used. Thus, the nomenclature of the compound is: Hexyne

## NCERT free solutions for class 10 science chapter 4 Carbon and its Compounds

Topic 4.3 Chemical Properties of carbon compounds

The conversion of ethanol to ethanoic acid is :

Since there is an addition of oxygen in the reaction, this is an oxidation reaction.

A mixture of oxygen and ethyne is burnt for welding. But a mixture of ethyne and air is not used. This is because ethyne undergoes incomplete combustion in air giving a sooty flame.

In oxygen, ethyne gives a clean flame with temperature as high as 3300 K due to complete combustion.

## NCERT solutions for class 10 science chapter 4 Carbon and Its Compounds

Topic 4.4: Some Important Carbon Compounds - Ethanol and Ethanoic Acid

We can distinguish between alcohol and carboxylic acid by reacting them with carbonates/hydrogen carbonates. The acid reacts with hydrogen carbonate to liberate carbon dioxide which turns lime water milky.

$CH_3COOH + NaHCO_3 \rightarrow CH_3COONa + CO_2 + H_2O$

Whereas alcohol shows no evolution of gas when reacted with carbonates.

$C_2H_5OH + NaHCO_3 \rightarrow no\ reaction$

The oxidation reaction is the reaction in which oxygen is added or hydrogen is removed.

The substance which adds oxygen to others is known as oxidizing agents.

Example: AlkalinepPotassium permanganate

## Solutions for NCERT class 10 science chapter 4 Carbon and its Compounds

Topic 4.5: Soaps and Detergents

No, we will not be able to check if the water is hard sing detergents. This is because detergents give rich lather with both hard and soft water without forming any scum.

Soap molecules form spherical structures known as micelles. The oily dirt is trapped inside these micelles which remain suspended as colloid. Hence, to remove these micelles containing the dirt, the clothes are agitated.

## NCERT solutions for class 10 science chapter 4 Carbon and its Compounds- Exercise solutions

(a) 6 covalent bonds.
(b) 7 covalent bonds.
(c) 8 covalent bonds.
(d) 9 covalent bonds.

Ethane, with the molecular formula $C_{2}H_{6}$ has 7 covalent bonds.

(b) It has 1 ($C-C$) and 6($C-H$) bonds.

(a) carboxylic acid.
(b) aldehyde.
(c) ketone.
(d) alcohol.

Butanone is a four-carbon compound with the functional group ketone. (c)

Butan-one: one is the suffix used for the functional group ketone.

(a) the food is not cooked completely.

(b) the fuel is not burning completely.

(c) the fuel is wet.

(d) the fuel is burning completely.

While cooking, if the bottom of the vessel is getting blackened on the outside, it means that the fuel is not burning completely.

Carbon has four electrons in its outermost shell and needs to gain or lose four electrons to attain noble gas configuration. Carbon overcomes this problem by sharing its valence electrons with other atoms of carbon or with atoms of other elements.

Of the four electrons, three are shared with hydrogen atoms and one with a chlorine atom. Thus it has three (C-H) and one (C-Cl) covalent bonds.

These bonds formed by the sharing of electrons are known as covalent bonds. Carbon, hydrogen, and chlorine attains the nearest noble gas configuration of Ne, He and Ar respectively.

The electron dot structure of ethanoic acid ($CH_3COOH$) is:

•  $H_{2}S$.

The electron dot structure of hydrogen sulphide ($H_{2}S$) is:

The electron dot structure of propanone ($CH_3COCH_3$) is:

The electron dot structure of $F_{2}$ is:

A series of carbon compounds having different numbers of carbon atoms but have the same functional group substituting the hydrogen atom is known as a homologous series.

For example, methane, ethane, propane, butane, etc. constitute the alkane homologous series. The general formula for alkanes is $C_nH_{2n+2}$Methane $CH_4$; Ethane $C_2H_6$; Propane $C_3H_8$ and so on.

Physical Properties

 Ethanol Ethanoic acid It has a pleasant smell. It has a pungent smell of vinegar. It has a low boiling point : 351 K. It has a comparatively high boiling point: 391 K.

Chemical Properties:

 Ethanol Ethanoic acid It has no action on litmus paper. It turns blue litmus to red. no reaction with $NaHCO_3$ Liberates $CO_2$ when reacted with $NaHCO_3$

A soap is a sodium or potassium salt of long-chain fatty acids. It has one polar hydrophilic end and one non-polar hydrophobic end. These molecules have a unique orientation inside water in form of clusters of molecule in which hydrophobic ends are in the interior of the cluster and ionic ends on the surface of cluster thus keeping the hydrocarbon portion out of water. This formation is known as Micelle. Soap in the form of a micelle is able to clean, as the oily dirt is collected in the centre of the micelle.

No, micelle formation does not take place in ethanol because the alkyl chain of soap becomes soluble in alcohol.

Carbon compounds have high calorific values. Therefore, carbon and its compounds are used as fuels for most applications. They give a lot of heat and light when burnt in air. Saturated hydrocarbons like methane burn with a clean flame without any smoke and are thus environmentally friendly.

Hard water contains calcium and magnesium salts. When soap is added with hard water, it reacts with the calcium and magnesium ions of hard water to form an insoluble substance called scum.  To overcome this problem, detergents are used.

Soap is basic in nature and hence will turn red litmus blue. However it will have no effect on blue litmus paper.

The conversion of unsaturated hydrocarbon to saturated hydrocarbon by the addition of hydrogen in the presence of nickel catalyst is called hydrogenation. This reaction is commonly used in hydrogenation of vegetable oil into vegetable ghee.

Unsaturated hydrocarbons like alkenes and alkynes will undergo addition reactions. Therefore, $C_3H_6$  (alkene having $-C=C-$) and $C_2H_2$ (alkyne having $-C\equiv C-$) will give addition reactions.

Butter is a saturated compound and oil is an unsaturated compound.

Test: When oil is added to a test tube containing alkaline potassium permanganate solution $KMnO_4$, the pink colour of the solution disappear. Therefore, cooking oil causes decolourisation of the solution. This does not happen in case of butter.

A soap is a sodium or potassium salt of long-chain fatty acids. It has one polar hydrophilic end and one non-polar hydrophobic end. When soap is at the surface of the water, the hydrophobic tail of soap being nonsoluble in water protrudes out of the water with the ionic end in water.

When there is no more space for soap molecules on the surface, these molecules create a unique orientation inside water in form of clusters in which hydrophobic ends are in the interior of the cluster and ionic ends on the surface of cluster thus keeping the hydrocarbon portion out of water. This formation is known as Micelle.

Soap in the form of a micelle is able to clean, as the oily dirt is collected in the centre of the micelle.The ionic ends in the micelles remain attached to water. When the dirty clothes are agitated in a soap solution, the oily dirt particles entrapped by soap micelles get dispersed in water and the clothes get cleaned.

## NCERT Solutions for Class 10 Science - Chapter wise

 Chapter No. Chapter Name Chapter 1 NCERT free solutions for class 10 science chapter 1 Chemical Reactions and Equations Chapter 2 Solutions for NCERT class 10 science chapter 2 Acids, Bases, and Salts Chapter 3 NCERT textbook solutions for class 10 science chapter 3 Metals and Non-metals Chapter 4 NCERT solutions for class 10 science chapter 4 Carbon and its Compounds Chapter 5 CBSE NCERT solutions for class 10 science chapter 5 Periodic Classification of Elements Chapter 6 NCERT free solutions for class 10 science chapter 6 Life Processes Chapter 7 Solutions for NCERT class 10 science chapter 7 Control and Coordination Chapter 8 NCERT textbook solutions for class 10 science chapter 8 How do Organisms Reproduce? Chapter 9 CBSE NCERT solutions for class 10 science chapter 9 Heredity and Evolution Chapter 10 Solutions for NCERT class 10 science chapter 10 Light Reflection and Refraction Chapter 11 NCERT free solutions for class 10 science chapter 11 The Human Eye and The Colorful World Chapter 12 NCERT solutions for class 10 science chapter 12 Electricity Chapter 13 CBSE NCERT solutions for class 10 chapter 13 Magnetic Effects of Electric Current Chapter 14 NCERT free solutions for class 10 science chapter 14 Sources of Energy Chapter 15 NCERT textbook solutions for class 10 science chapter 15 Our Environment Chapter 16 NCERT solutions for class 10 science chapter 16 Sustainable Management of Natural Resources

## NCERT Solutions for Class 10 - Subject Wise

 NCERT Solutions for Class 10 Maths NCERT Solutions for Class 10 Science

## How NCERT solutions for class 10 science chapter 4 Carbon and its Compounds will help you to score well in exams

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