Yes, soap does "stick" to water in the sense that it readily bonds with it.
Why Soap Bonds with Water
Soap molecules have a unique structure that allows them to interact favorably with both water and oils. These molecules are often described as having two distinct parts:
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Hydrophilic Head: This part of the soap molecule is "water-loving" (hydrophilic). It is attracted to water molecules and readily bonds with them through electrostatic interactions and hydrogen bonding.
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Hydrophobic Tail: This part of the soap molecule is "water-fearing" (hydrophobic). It prefers to associate with oils, fats, and other non-polar substances.
How This Affects Cleaning
This dual nature is what makes soap an effective cleaning agent:
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Dissolving in Water: The hydrophilic heads of the soap molecules allow the soap to dissolve in water.
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Attracting Grease and Oil: The hydrophobic tails avoid water and instead cluster around grease and oil particles.
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Forming Micelles: The soap molecules arrange themselves into tiny spherical structures called micelles, with the hydrophobic tails pointing inwards towards the grease and oil, and the hydrophilic heads pointing outwards towards the water.
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Lifting Away Dirt: The micelles encapsulate the grease and oil, allowing them to be lifted away from the surface being cleaned and washed away with water.
Conclusion
Soap doesn't simply "stick" to water superficially; it forms a chemical bond with it via the hydrophilic head of the soap molecule, which is crucial for its function as a cleaning agent. This interaction, combined with the hydrophobic interaction with grease and oil, allows soap to effectively remove dirt and grime.
