Chapter 9: Carbon Compounds – Maharashtra State Board Class 10 Notes

Welcome to your detailed science notes for Chapter 9 – Carbon Compounds. This chapter is extremely important for scoring high in the Class 10 Maharashtra Board Science exam. Let's dive deep into the world of organic chemistry and understand the role of carbon and its compounds in our daily lives.

🔹 Introduction to Carbon

Carbon is one of the most versatile elements found in nature. It can form an enormous variety of compounds due to the following properties:

• Catenation: Ability to form long chains with itself.
• Tetravalency: Forms four covalent bonds with other atoms.
• Multiple bonding: Can form single, double, or triple bonds.

🔸 Covalent Bonding in Carbon

Carbon forms covalent bonds by sharing electrons with other atoms. It does not donate or accept electrons like ionic bonds.

Example: Methane (CH₄) – Carbon shares its four electrons with four hydrogen atoms.

🔹 Types of Carbon Compounds

Carbon compounds can be broadly classified as:

• Saturated Compounds (Alkanes): Contain single bonds only. Example: Ethane (C₂H₆).
• Unsaturated Compounds:
  • Alkenes: One or more double bonds. Example: Ethene (C₂H₄).
  • Alkynes: One or more triple bonds. Example: Ethyne (C₂H₂).

🔸 Homologous Series

A homologous series is a group of organic compounds having:

• Same functional group
• Same general formula
• Similar chemical properties
• Successive members differ by a –CH₂– group

🔹 Functional Groups

Functional groups are specific atoms or groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.

• –OH: Alcohol group
• –COOH: Carboxylic acid
• –CHO: Aldehyde
• –CO–: Ketone
• –X (X = Cl, Br, I): Halides

🔸 Important Reactions of Carbon Compounds

• Combustion: Carbon compounds burn in air to give CO₂, water, and energy.
• Oxidation: Alcohols are oxidized to carboxylic acids.
• Addition: Unsaturated compounds (alkenes/alkynes) undergo addition of hydrogen, halogens etc.
• Substitution: In alkanes, a hydrogen atom may be replaced by a halogen.

🔹 Ethanol and Ethanoic Acid

Ethanol (CH₃CH₂OH) is used in medicines, perfumes, and as a fuel. It reacts with sodium to give hydrogen gas and sodium ethoxide.

Ethanoic Acid (CH₃COOH) is the main component of vinegar and turns blue litmus red.

🔸 Soaps and Detergents

Soaps are sodium or potassium salts of fatty acids. They are biodegradable. Detergents are man-made and can work in hard water but may be non-biodegradable.