what makes one end of a soap molecule hydrophilic?

Question

Also, why does this structure, help get clothes clean?

Answer 1

The functional groups in the molecule make something hydrophilic or hydrophobic. In order for one end to be hydrophilic it needs a polar group that has properties that are similar to water. OH- would be an example. Non polar groups like long carbon chains are the the opposite and prefer to avoid water.

Answer 2

Soap has two ends which differ. One end is a long alkyl chain and is hydrophobic. The other end is ionic. It is either an ionized sufate such as a sodium sulfate or a salt of a carboxylic acid. The ionic end is hydrophilic because it a salt and therefore very soluable in H2O. Hope this helps.

Answer 3

One end of the soap molecule is hydrophilic because it is polar (has an uneven distribution of electrical charge).
Wikipedia has a partial chemical equation for soap:
"(fatty end) :CH3-(CH2)n - COONa: (water soluble end)
The hydrocarbon ("fatty") portion dissolves dirt and oils, while the ionic end makes it soluble in water. Therefore, it allows water to remove normally-insoluble matter by emulsification." (http://en.wikipedia.org/wiki/Soap)

Answer 4

The COO-Na+ or COO-K+ ionic end can form attractions to polar water molecules, thus making it soluble and hydrophillic.

Answer 5

For soap specifically, the ionized carboxylate group.

For syndets in general, anything hydrophilic - charge (quaternized nitrogen, guanidinium; carboxylate, sulfate and sulfonate, phosphate and phosphonate...), polarity (polyoxyethylene), hydrogen bonding (sugar re octyl- and decyl-glucopyranoside).