Courses
Courses for Kids
Free study material
Offline Centres
More
Store Icon
Store
seo-qna
SearchIcon
banner

Detergents are less or non-biodegradable when compared with soaps. For detergents to be biodegradable in nature, the non polar part of the molecule should:
A) Consist of a hydrocarbon with more branching
B) Consist of a hydrocarbon with more branching and unsaturation
C) Have straight or open chained hydrocarbons D) Be replaced by aromatic rings substituted by alkyl groups

Answer
VerifiedVerified
503.7k+ views
like imagedislike image
Hint: Detergents are synthetic compounds, generally ammonium or sulfate salts of long chain carboxylic acids. These synthetic compounds can not be broken down into simple molecules by microbes and hence they are non biodegradable.

Complete step-by-step answer:
- Biodegradable substances are those substances which can be decomposed by the action of microorganisms. Non-Biodegradable substances are those substances which cannot be decomposed by the action of microorganisms.
- Surfactants are compounds that lower the surface tension between molecules. This is caused due to the attraction of the particles in the surface layer by the bulk of the liquid. Surfactants may act as detergents, emulsifiers,etc.
- Detergent is one such surfactant that is formed from long chain alkyl groups. . Like soap, these contain both hydrophobic and hydrophilic parts. The hydrophobic part is the nonpolar in nature whereas the hydrophilic part is the polar part of the molecule.
- Discussing option A, If the non polar part of the molecule consists of a hydrocarbon with more branching, then more amount of energy will be needed to break the more number of bonds. Clearly, this will make the detergent more non- biodegradable.
- Discussing option B, if it has more unsaturation, then also we know it needs more energy to dissociate or break the double/triple bonds in between them. Clearly, this too will make the detergent more non- biodegradable.
- Discussing option C, if it has straight and opened chains of hydrogen, then it will need somewhat less amount of energy to break the bonds. Thus, it will be feasible for the detergents to be biodegradable.
- Discussing option D, aromatic chains with alkyl groups are more stable, and thus need a very high amount of energy to break down. That is not feasible for any microorganismes, since that type of energy will only be provided from certain chemical reactions that liberate the same/ more energy needed to break the bonds.
The answer is C.

Additional information: Soap is basically sodium and potassium salts of long fatty acid chains. The end of the molecule to which the sodium ion is attached is polar in nature. It means that it will readily dissolve in water as water is also polar in nature. As it dissolves in water easily, thus it is called as hydrophilic or water- loving. The alkyl chain is nonpolar hence it does not dissolve in water. Thus, this part is hydrophobic or water- hating.

Note: Branched alkyl groups do not dissociate easily as it becomes difficult to break down the bonds in between them. Detergents are basically long chained, thus compounds with more branches will be difficult to dissociate and will be non- biodegradable in nature.
Latest Vedantu courses for you
Grade 11 Science PCM | CBSE | SCHOOL | English
CBSE (2025-26)
calendar iconAcademic year 2025-26
language iconENGLISH
book iconUnlimited access till final school exam
tick
School Full course for CBSE students
PhysicsPhysics
ChemistryChemistry
MathsMaths
₹41,848 per year
Select and buy