Question

Which of the following is not an example of a synthetic detergent?

• A. Cetyltrimethylammonium bromide
• B. Sodium stearate
• C. Sodium laurylsulfate
• D. Sodium dodecylbenzenesulfonate

Hint:

Synthetic detergents are typically anionic or nonionic surfactants, while soaps (like sodium stearate) are naturally derived and not considered synthetic detergents.

Answer 1

The Correct Option is B

Step 1: Understand Synthetic Detergents. 
Synthetic detergents are surfactants (surface-active agents) used as cleaning agents. They are typically classified into:
1. Anionic Surfactants: Negatively charged hydrophilic head and hydrophobic tail. Examples include sodium lauryl sulfate, sodium dodecylbenzenesulfonate, etc.
2. Cationic Surfactants: Positively charged hydrophilic head and hydrophobic tail. Examples include cetyltrimethylammonium bromide. 
Step 2: Analyze Each Option.
(1) Cetyltrimethylammonium bromide: 
A cationic surfactant.
Used in specialized applications, not in synthetic detergents.
Not an example of a synthetic detergent.
(2) Sodium stearate: 
A soap derived from natural fats and oils through saponification.
Not a synthetic detergent; soaps are naturally derived.
Not an example of a synthetic detergent.
(3) Sodium laurylsulfate: 
An anionic surfactant.
Commonly used in synthetic detergents and personal care products.
An example of a synthetic detergent.
(4) Sodium dodecylbenzenesulfonate: 
An anionic surfactant.
Widely used in synthetic detergents.
An example of a synthetic detergent.
Step 3: Identify the Correct Answer. 
Both options (1) and (2) are not examples of synthetic detergents. However, since the question asks for the single correct answer, and soaps are more commonly recognized as non-synthetic detergents, the best choice is: 
Final Answer: $ \boxed{2} $