Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?
Micelle formation takes place when soap is added to water because soap molecules have two ends with differing properties. One end is hydrophilic (interacts with water), while the other end is hydrophobic (interacts with hydrocarbons).
When soap is at the surface of water, the hydrophobic 'tail' is not soluble in water. Soap molecules align along the surface with the ionic end in water and the hydrocarbon 'tail' protruding out. Inside water, molecules orient to keep the hydrocarbon portion out of the water.
This leads to clusters called micelles, where hydrophobic tails are in the interior and ionic ends are on the surface. Micelles stay in solution as a colloid and do not precipitate due to ion-ion repulsion.
Regarding micelle formation in other solvents like ethanol, the provided context does not explicitly address this. The context discusses micelle formation in water and poses a question about micelle structure in hydrocarbon solvents, suggesting that micelle formation depends on solvent properties. However, specific information about ethanol is not provided in the given context.
Explanation
The answer explains micelle formation based on the textbook context which describes soap molecules having hydrophilic and hydrophobic ends. The hydrophobic tails cluster together inside water while ionic ends face outward, forming micelles. For the second part about ethanol, the context does not provide explicit information - it only discusses water as solvent and poses a question about hydrocarbon solvents. A complete answer would require additional textbook content about solvent properties.