MP Assistant Professor Exam 2022
Liquid dish washing detergents are of ----- type.
Liquid dishwashing detergents are of (C) Non-ionic
Explanation:
- Non-ionic detergents do not possess any electrical charge in their hydrophilic (water-attracting) heads.
- They are commonly used in liquid dishwashing formulations because they are low-sudsing, effective at removing grease, and less irritating to the skin compared to anionic surfactants.
- A typical example is a polyethylene glycol stearate or esters of high molecular weight alcohols.
Summary of other types:
| Type | Common Use |
|---|---|
| Anionic | Laundry detergents, soaps |
| Cationic | Hair conditioners, fabric softeners (due to germicidal properties) |
How Non-Ionic Detergents Work (Mechanism)
Non-ionic detergents remove grease through a process called emulsification. Unlike ionic detergents, they do not have a charge, which makes them highly effective in hard water because they do not form "scum" with calcium or magnesium ions.
The molecules consist of two parts:
- Hydrophobic tail: A long hydrocarbon chain that "hates" water but "loves" oil and grease.
- Hydrophilic head: A polar group (like an ethoxylate chain) that "loves" water.
The Cleaning Process:
- Adsorption: The hydrophobic tails stick into the grease on the plate.
- Micelle Formation: The detergent molecules surround the grease, forming a spherical structure called a micelle.
- Dispersion: The hydrophilic heads point outward into the water, allowing the entire grease globule to be lifted off the surface and rinsed away.
Related Topics
Emulsion and Emulsifying Agent
Cleansing Action of Detergent