A. Soap is an ionic compound that attracts the ions in greasysubstances B. Soap
ID: 675579 • Letter: A
Question
A. Soap is an ionic compound that attracts the ions in greasysubstances B. Soap has a long, nonpolar tail and polar "head group" thatallows it to dissolve in water. C. Soap is made up of long, hydrocarbon chains that can wraparound a greasy molecule. D. Soap has groups that allow it to hydtrogen bond with waterand dissolve readily. A. Soap is an ionic compound that attracts the ions in greasysubstances B. Soap has a long, nonpolar tail and polar "head group" thatallows it to dissolve in water. C. Soap is made up of long, hydrocarbon chains that can wraparound a greasy molecule. D. Soap has groups that allow it to hydtrogen bond with waterand dissolve readily.Explanation / Answer
(B) is the most appropriate answer. Soap contains both hydrophobic and hydrophilic part (this is knownas amphiphatic molecule) Grease and oil stains are hydrophobicmolecules. The hydrophobic part of the soap can form hydrophobicinteraction with grease and oil stains. Water tends to hydrate the hydrophilic portion of an amphiphile,but it also tends to exclude the hydrophobic portion. Amphiphilesconsequently tend to form structurally ordered aggregates. Micellesare globules up to several thousand amphiphilic molecules arrangedso that the hydrophilic groups at the globule surface can interactwith aqueous solvent while the hydrophobic groups associate at thecenter, away from the solvent. Alternatively, amphiphilic moleculesmay arrange themselves to form bilayered sheets or vesicles inwhich the polar groups face the aqueous phase. In both micelles andbilayers, the aggregate is stabilized by the hydrophobic effect,the tendency of water to exclude hydrophobic groups. So, the above properties of soap and water allow the cleansingaction of soap to function efficiently. Hope this helps!