Hydrophobic substances are polar or non-polar?
They are non-polar!
Iodine is not soluble in water because iodine is nonpolar and water is polar. According to the "Like dissolve like" expression, nonpolar substances are soluble with nonpolar substances and polar substances are soluble with polar substances, but nonpolar substances are not soluble with polar substances.
Substances are hydrophobic because they are nonpolar. Nonpolar molecules are made up of elements with little difference in their electronegativities so they do not have charges or partial charges. Water is a polar molecule so it tends to be attracted to other molecules that are polar as well. This is often summed up as "like attracts like". Some examples of hydrophobic molecules include fats and oils which are nonpolar because they have large hydrophobic hydrocarbon…
Triglycerides are just fats, which have both nonpolar and polar parts. The areas with carbon-oxygen bonds are fairly polar, while the carbon-hydrogen bonded areas are nonpolar. Since there are extensive chains of carbon-hydrogen bonds in triglycerides, they are generally nonpolar and don't dissolve in water, a polar liquid. As the saying goes, "like dissolves like," and hence, nonpolar substances dissolve in nonpolar substances, polar in polar. In the case of water, you'll often hear of…
Oil and water do not mix because the triglyceride bonds have a hydrophobic (meaning does not like water) ends and therefore it will not react (or mix) with water. Water and oil don't mix because water is a polar substance and oil is nonpolar. Polar substances will only dissolve other polar substances or ionic substances, but will not dissolve nonpolar substances. Remember "Like dissolves like."
Fats, as well as organic compounds, are nonpolar substances. Water, however, is a polar substance. Nonpolar substances dissolve nonpolar substances and polar substances dissolve polar substances (like dissolves like) because each are more attracted to molecules of similar structure than of different structure.
the rule of thumb is "Like dissolves like". What this means is that polar substances dissolve polar substances, and nonpolar substances dissolve nonpolar substances. For instance, common tablesalt (NaCl) has an ionic bond that will dissociate in polar liquid like water (H2O), but not in a nonpolar liquid like oil.
Polar substances will dissolve other polar substances.* Ionic substances will dissolve other ionic substances Nonpolar substances will dissolve other nonpolar substances. *Water is called the universal solvent because it can dissolve both polar and ionic substances. (Although not all ionic substances will be dissolved by water.)
Yes, they do. Phospholipids contain a hydrophilic (polar) head and a hydrophobic (nonpolar) tail. The hydrophilic (polar) head contains the phosphate groups, which account for the reason why the head is polar since each phoshpate has a net charge of -2. The tail consists of long chains of hydrocarbons, which are nonpolar/hydrophobic due to the symmetry of the chains.
Typically, the rule "like dissolves like" applies to solvents. Substances with like bonds will be soluble in one another. Thus, polar substances dissolve polar substances, while nonpolar substances dissolve nonpolar substances. This results from the nature of the bonds that are broken and formed in the process of solvation, and their relative energies.
Oil and water will not mix as water is a polar substance and oil is nonpolar. Polar substances will only dissolve other polar substances or ionic substances, but not nonpolar substances. Thus, they stay separate, and water is more dense then oil, which is why the oil floats (same principals as to why anything floats)