
Which one of the following statements is incorrect about soaps?
(A) Soaps are biodegradable
(B) Soaps are sodium salts of higher fatty acids
(C) Soaps are prepared from natural oils and fats
(D) Soaps can be used in acidic solutions
Answer
139.8k+ views
Hint: Soap is a combination of sodium salts and higher fatty acids that are natural. These are chemical cleansers prepared from natural fats and oils which are obtained from plants and animals. These are salts and form insoluble fatty acid chains when acidified further.
Complete step-by-step answer:
Soaps are derivatives of fatty acids in the form of covalent salt made from common vegetable oils or natural fats. Soaps are the potassium or sodium salts of long-chain fatty carboxylic acids. They are surfactants i.e. these compounds reduce the surface tension between a liquid and another substance and thus help in the emulsification of oils in water.
Natural fats and oils present in soaps can be easily broken down into simpler molecules by microorganisms and so we can say that soaps are biodegradable.
Soaps are generally prepared by the process of saponification of fats and oils. This process involves heating oils and fats and reacting them with a liquid alkali or base to produce soap plus water along with glycerine. The carboxylate end of the soap molecule is hydrophilic (water-loving) whereas the hydrocarbon tail is hydrophobic (water-hating).
This is the structure of soap.
Soaps cannot be used in acidic conditions because they tend to lose their cleansing ability due to the formation of insoluble long-chain fatty acids. The pH of these fatty acids will then decrease to less than 7, which is bad for clothes.
Hence, the correct option is (D).
Note: Soaps do not work well with hard water that contains calcium or magnesium salts. It reacts with calcium and magnesium ions to form white precipitate which is referred to as scum and soap goes waste or can’t be used anymore.
Complete step-by-step answer:
Soaps are derivatives of fatty acids in the form of covalent salt made from common vegetable oils or natural fats. Soaps are the potassium or sodium salts of long-chain fatty carboxylic acids. They are surfactants i.e. these compounds reduce the surface tension between a liquid and another substance and thus help in the emulsification of oils in water.
Natural fats and oils present in soaps can be easily broken down into simpler molecules by microorganisms and so we can say that soaps are biodegradable.
Soaps are generally prepared by the process of saponification of fats and oils. This process involves heating oils and fats and reacting them with a liquid alkali or base to produce soap plus water along with glycerine. The carboxylate end of the soap molecule is hydrophilic (water-loving) whereas the hydrocarbon tail is hydrophobic (water-hating).

This is the structure of soap.
Soaps cannot be used in acidic conditions because they tend to lose their cleansing ability due to the formation of insoluble long-chain fatty acids. The pH of these fatty acids will then decrease to less than 7, which is bad for clothes.
Hence, the correct option is (D).
Note: Soaps do not work well with hard water that contains calcium or magnesium salts. It reacts with calcium and magnesium ions to form white precipitate which is referred to as scum and soap goes waste or can’t be used anymore.
Latest Vedantu courses for you
Grade 7 | CBSE | SCHOOL | English
Vedantu 7 CBSE Pro Course - (2025-26)
School Full course for CBSE students
₹42,500 per year
EMI starts from ₹3,541.67 per month
Recently Updated Pages
Average fee range for JEE coaching in India- Complete Details

Difference Between Rows and Columns: JEE Main 2024

Difference Between Length and Height: JEE Main 2024

Difference Between Natural and Whole Numbers: JEE Main 2024

Algebraic Formula

Difference Between Constants and Variables: JEE Main 2024

Trending doubts
JEE Main 2025 Session 2: Application Form (Out), Exam Dates (Released), Eligibility, & More

JEE Main 2025: Derivation of Equation of Trajectory in Physics

JEE Main Exam Marking Scheme: Detailed Breakdown of Marks and Negative Marking

Learn About Angle Of Deviation In Prism: JEE Main Physics 2025

Number of sigma and pi bonds in C2 molecule isare A class 11 chemistry JEE_Main

Electric Field Due to Uniformly Charged Ring for JEE Main 2025 - Formula and Derivation

Other Pages
NCERT Solutions for Class 11 Chemistry Chapter 9 Hydrocarbons

NCERT Solutions for Class 11 Chemistry Chapter 7 Redox Reaction

JEE Advanced Marks vs Ranks 2025: Understanding Category-wise Qualifying Marks and Previous Year Cut-offs

NCERT Solutions for Class 11 Chemistry Chapter 5 Thermodynamics

Hydrocarbons Class 11 Notes: CBSE Chemistry Chapter 9

NCERT Solutions for Class 11 Chemistry In Hindi Chapter 1 Some Basic Concepts of Chemistry
