Position of nonpolar and parts in micells is

Options

A. Polar at outer surface but nonpolar at inner surface
B. Polar at inner surface but nonpolar at outer surface
C. Distributed all over the surface
D. Present in the surface only

Answer

A

Explanation

Let's consider soap solution. Soap is sodium or potassium salt of a higher fatty acid and may be represented as `RCOO^(-)Na^(+)` e.g., sodium stearate viz. `CH_(3)(CH_(2))_(16)COO^(-)Na^(+)` which is a major component of many bar soaps. When dissolved in water, it dissociates into `RCOO^(-)` and `Na^(+)` ions. The `RCOO^(-1)` ions consist of two parts: long hydrocarbon chain `R` (also called non polar 'tail') which is hydrophobic (water repelling) and polar group `COO^(-)` (also called polarionic 'head') which is hydrocarbon chains `R` staying away from it, and remain at the surface, but at higher concentration these are pulled into the bulk of the solution and aggregate in a spherical from with their hydrocarbon chains pointing towards the centre with `COO^(-)` part pointing outward on the surface. An aggregate thus formed is known as 'ionicmicelle' .