Access free live classes and tests on the app
Download
+
Unacademy
  • Goals
    • AFCAT
    • AP EAMCET
    • Bank Exam
    • BPSC
    • CA Foundation
    • CAPF
    • CAT
    • CBSE Class 11
    • CBSE Class 12
    • CDS
    • CLAT
    • CSIR UGC
    • GATE
    • IIT JAM
    • JEE
    • Karnataka CET
    • Karnataka PSC
    • Kerala PSC
    • MHT CET
    • MPPSC
    • NDA
    • NEET PG
    • NEET UG
    • NTA UGC
    • Railway Exam
    • SSC
    • TS EAMCET
    • UPSC
    • WBPSC
    • CFA
Login Join for Free
avtar
  • ProfileProfile
  • Settings Settings
  • Refer your friendsRefer your friends
  • Sign outSign out
  • Terms & conditions
  • •
  • Privacy policy
  • About
  • •
  • Careers
  • •
  • Blog

© 2023 Sorting Hat Technologies Pvt Ltd

CBSE Class 12 » CBSE Class 12 Study Materials » Chemistry » Hydrocarbons
CBSE

Hydrocarbons

Hydrocarbons are organic compounds consisting only of hydrogen and carbon atoms. They are found in many places, including crude oil and natural gas.

Table of Content
  •  

Introduction

Organic compounds such as hydrocarbons comprise only hydrogen and carbon atoms. They are group 14 hybrids containing hydrogen and group 14 carbon atoms; carbon, silicon, germanium, tin and lead. Carbon has 4 electrons, so it has to form exactly 4 bonds to be stable. Another class of hydrocarbons are aromatic hydrocarbons, including alkanes, naphthenes, and alkyne-based compounds. Hydrocarbons can form more complex compounds such as cyclohexane by combining with themselves. This is called chaining.

What are Hydrocarbons?

In organic chemistry, a hydrocarbon is an organic compound made entirely of hydrogen and carbon, hence they are Group 14 hydride. A hydrocarbon with one hydrogen atom removed is a functional group called a hydrocarbyl. Aromatics hydrocarbons (arenes), alkanes, alkenes, cycloalkanes, and alkyne-based compounds are different types of hydrocarbons. Most hydrocarbons found on Earth are naturally present in crude oil, where decomposing organic matter produces large amounts of carbon and hydrogen that, when combined, can work together to form seemingly infinite chains.

Types of Hydrocarbons

Apart from alcohols, aldehydes and carboxylic acids, hydrocarbons are the simplest organic compounds and can be divided into the following categories:

1. Saturated Hydrocarbons

Saturated hydrocarbon compounds contain only C-C single bonds, and all carbons in them are fully utilised. It is less reactive. Alkanes are saturated hydrocarbons.

Alkanes

These are singly bonded, when n=1 (only one carbon atom). Methane, CH4 are examples of alkanes. When n=2, each carbon forms 4 covalent bonds and forms C2H6. Likewise, C3H8 is formed; all these compounds (methane, ethane, and propane, respectively) are alkanes. Hence, the formula for alkanes is CnH(2n+2).

Many carbon atoms derive the names for organic compounds, where the presence of one carbon atom refers to meth, 2 is eth, 3 is prop, 4 is buy, 5 is pent, 6 is hex, 7 is hept, 8 is oct, and 9 is non, and the presence of 10 carbon atoms means dec.

 

2. Unsaturated Hydrocarbons

Here at least two carbon atoms are linked by double or triple bonds.

Unsaturated hydrocarbons are more reactive because double and triple bonds are easily broken and added. Alkenes and alkynes are two unsaturated hydrocarbons, where alkenes contain at least one double bond and alkynes contain at least one triple bond.

Alkenes

These compounds have double bonds. If n = 1, we have no valid alkene. When n=2, C2H4 (ethene) is produced, and when n=3, C3H6 (propene) is produced. Hence, the formula for alkenes is CnH(2n) .

Alkynes

They are also unsaturated hydrocarbons with triple bonds. It is not a valid alkyne when n=1; it forms C2H2 (ethyne) when n=2, and C3H4 (propyne) when n=3. Hence, the formula of an alkyne is CnH(2n-2) . All alkynes have the suffix “yne”. The suffix is “ene” for alkene, and “ane” for alkane.

3. Cyclic or Closed Hydrocarbons

Cyclic hydrocarbons are hydrocarbons in which carbon chains are linked themselves into rings. All carbon-carbon bonds are single bonds in a cyclic hydrocarbon. Like other alkanes, naphthenes are saturated compounds. Cycloalkanes have the general formula CnH2n. The simplest cycloalkane is cyclopropane, which is a ring with three carbon atoms.

Examples-  Cyclohexane is a six-carbon cycloalkane, cyclopropane, the simplest cycloalkanes.

Example of Hydrocarbons

Methane and propane are gaseous hydrocarbons, hexane and benzene are liquid hydrocarbons,  paraffin wax and naphthalene are hydrocarbons with low melting points, and polystyrene, polypropylene and polyethylene are polymeric chain hydrocarbons.

Uses of Hydrocarbons

Hydrocarbons have a number of uses. Some of them are as follows:

  1. These are used as fuel sources such as methane (a component of natural gas).

  2. Gasoline, jet fuel, and naphtha are aliphatic hydrocarbons widely used in various industries.

  3. Roofing compounds, bitumen or pavement compositions and wood preservatives are also different forms of hydrocarbons.

  4. Their applications as large-scale non-fuels such as ethane and propane are derived from oil and natural gas. These two gases can then be converted into ethylene and propylene.

  5. Natural hydrocarbons are found in Brazilian stingless bees, and they leave a distinctive hydrocarbon odour that helps distinguish kin from non-kin.

Conclusion

Hydrocarbons are the simplest organic compounds, containing only carbon and hydrogen, but they can be straight or branched, with the same empirical formula but different properties. Chemical changes result in hydrocarbons that produce products that may be completely different in composition from the starting hydrocarbons—except for isomerisation reactions in which straight-chain hydrocarbons are converted to branched-chain hydrocarbons.

The chemical properties of hydrocarbons show the ability of hydrocarbons to undergo chemical changes or reactions through the hydrocarbon structure. The physical properties of hydrocarbons can be perceived or measured without changing the composition of matter. Physical properties are used to outline and perceive substances. Physical properties of interest in the current context include boiling point, melting point, specific gravity, vapour density, flash point, ignition temperature, and dew point.

Crack CBSE Class 12 with Unacademy

Get subscription and access unlimited live and recorded courses from India’s best educators

  • Structured syllabus
  • Daily live classes
  • Ask doubts
  • Tests & practice
Learn more

Notifications

Get all the important information related to the CBSE Class 12 Examination including the process of application, important calendar dates, eligibility criteria, exam centers etc.

CBSE Class 12 Exam Pattern
CBSE Class 12 Results 2023
CBSE Class 12 Syllabus
See all

Related articles

Learn more topics related to Chemistry
Wave Nature of Matter

Wave nature of matter and dual nature of matter and light

Water Pollution

What is water pollution, causes of water pollution, effects of water pollution, sources of water pollution, FAQs, etc.

Uses of hydrogen chloride

Learn about the uses of hydrogen chloride and its properties in detail in the article. You will know more about the formation of hydrogen chloride and hydrochloric acid.

Uses of Aluminium, Copper, Zinc and Iron

This study material discusses the uses of Aluminium, uses of Copper, uses of Zinc, uses of Iron, molecular masses, atomic weights, and atomic numbers.

See all
Access more than

6,582+ courses for CBSE Class 12

Get subscription

Trending Topics

  • Assertive Sentence
  • First 20 Elements
  • Charging By Induction
  • Dialogue Writing
  • What Are Tertiary Activities
  • Pedigree Analysis
  • Secondary Activities
  • Disintegration Of Soviet Union
combat_neetug

Important Links

  • NCERT Solutions
  • NCERT Books
  • Physics Formulas
  • Maths Formulas
  • Chemistry Formulas
rankpredictor_neetug
Download NEET 2022 question paper
Company Logo

Unacademy is India’s largest online learning platform. Download our apps to start learning


Starting your preparation?

Call us and we will answer all your questions about learning on Unacademy

Call +91 8585858585

Company
About usShikshodayaCareers
we're hiring
BlogsPrivacy PolicyTerms and Conditions
Help & support
User GuidelinesSite MapRefund PolicyTakedown PolicyGrievance Redressal
Products
Learner appLearner appEducator appEducator appParent appParent app
Popular goals
IIT JEEUPSCSSCCSIR UGC NETNEET UG
Trending exams
GATECATCANTA UGC NETBank Exams
Study material
UPSC Study MaterialNEET UG Study MaterialCA Foundation Study MaterialJEE Study MaterialSSC Study Material

© 2025 Sorting Hat Technologies Pvt Ltd

Unacademy
  • Goals
    • AFCAT
    • AP EAMCET
    • Bank Exam
    • BPSC
    • CA Foundation
    • CAPF
    • CAT
    • CBSE Class 11
    • CBSE Class 12
    • CDS
    • CLAT
    • CSIR UGC
    • GATE
    • IIT JAM
    • JEE
    • Karnataka CET
    • Karnataka PSC
    • Kerala PSC
    • MHT CET
    • MPPSC
    • NDA
    • NEET PG
    • NEET UG
    • NTA UGC
    • Railway Exam
    • SSC
    • TS EAMCET
    • UPSC
    • WBPSC
    • CFA

Share via

COPY