Biology Forums - Study Force

What properties make them insoluble?

Hydrocarbons are non polar.
Water is polar.
Like devolves like.
Therefore non polar things do NOT dissolve in polar things (unless the hydrocarbon is very small...but that is a different story about molecules misbehaving).

Hydrocarbons are organic compounds that consist of only C and H atoms. They include the alkanes, alkenes, alkynes, and aromatic hydrocarbons. Because of their relatively non-polarity, all hydrocarbons are insoluble in water.

Water is a polar solvent. Hydrocarbons are not so mostly they are no soluble in aqueous solutions.

As carbon number increases the polarity decreases. As water is a polar solvent molecules with higher C number will have lower solubility due to lower polarity.

Hydrocarbons have non-polar electronegativities while water is very polar!

Hydrocarbons are nonpolar, therefore they do not react with water which is polar. Think of it as like dissolves like. Polar would then dissolve polar, and so on. As you increase the number of Carbons in a hydrocarbon chain you become more and more nonpolar, making it more difficult to be soluble in water.

Hydrocarbons are made up of carbon and hydrogen atoms linked through nonpolar covalent bonds. Such bonds are generally though of as very strong and difficult to break. This makes hydrocarbon insoluble in water.

Similarly to previous responses, hydrocarbons are made up of Carbon and Hydrogen atoms that are linked via nonpolar covalent bonds. Due to these bonds, the hydrocarbons are non-polar. Non-polar molecules do not interact with water since water is polar (Oxygen in water is partial negative while the two Hydrogens are partial positive) and dissolves polar molecules easily (like dissolves like). Think of it as fat molecules, the outer exterior of fat molecules are made up of hydrocarbons. When fat molecules are in water, they temporarily disrupt the weak hydrogen bonds between water molecules. Water molecules then reorient themselves to form the max number of hydrogen bonds and become ordered around the nonpolar fat molecules - this results in a decrease in entropy of water. The fat molecules then associate together, releasing any ordered water molecules around individual nonpolar molecules to increase entropy.