Detergents are manufactured with straight hydrocarbon chains, is to make them

Analysis

The question asks why manufacturers prefer using straight hydrocarbon chains when producing detergents. This is a classic environmental chemistry question often found in JAMB and WASSCE syllabi.

Concept Explanation

Detergents are synthetic cleaning agents. Early detergents were made with branched hydrocarbon chains. These branched chains were resistant to bacterial decomposition, meaning they did not break down easily in water bodies, leading to persistent water pollution and excessive foaming in rivers.

To solve this, manufacturers switched to straight-chain (linear) alkylbenzenes. Straight chains are much easier for microorganisms (bacteria) to break down. When a substance can be broken down by biological processes (like bacteria), it is said to be biodegradable.

Step-by-Step Solution

1. Identify the problem: Branched-chain detergents cause environmental pollution because they are "non-biodegradable" (they persist in the environment).
2. Analyze the solution: By using straight hydrocarbon chains, the molecular structure becomes more accessible to the enzymes produced by bacteria.
3. Connect to the options: • Solubility (A): While straight chains affect solubility, the primary manufacturing goal for using them is environmental safety. • Biodegradability (B): Straight chains allow bacteria to break the molecules down into simpler, harmless substances. • Cost (C): Straight-chain detergents are often more expensive to produce than branched ones, so this is not the reason. • Foaming (D): Both branched and straight chains produce foam; the straight chain does not make it "more" foamy.

Conclusion

The primary reason for using straight hydrocarbon chains in the production of detergents is to ensure they can be broken down by microorganisms in the environment, preventing pollution.

Exam Tip: Always remember the "Straight = Biodegradable" rule for detergents. If you see a question about "branched" chains, the answer is almost always that they are "non-biodegradable" or cause "water pollution."