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Why does surface water disperse when touched with soap?

User Onionpsy
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2 Answers

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Answer:

In a soap-and-water solution the hydrophobic (greasy) ends of the soap molecule do not want to be in the liquid at all. Those that find their way to the surface squeeze their way between the surface water molecules, pushing their hydrophobic ends out of the water. This separates the water molecules from each other.

Step-by-step explanation:

User Bryan Denny
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The end of the detergent molecule which attaches to fat (grease) repels water molecules. It is known as hydrophobic, meaning "water fearing." By attempting to move away from the water molecules, the hydrophobic ends of the detergent molecules push up to the surface. This weakens the hydrogen bonds holding the water molecules together at the surface. The result is a break in the surface tension of the water.

User Thetrutz
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