It’s a common question, why are hydrocarbons insoluble in water? The answer to this question is found by looking at the chemical and physical properties of hydrocarbons. Hydrocarbons are organic compounds that contain only hydrogen and carbon atoms. They don’t dissolve in water because they have different polarities than the molecules of water do. When two polar molecules come together, the stronger of the two forces wins. In this case, water is a lot more strongly hydrophilic than hydrocarbons are (readily soluble in water). The strength and polarity also play into how quickly they mix but that’s not what we’re talking about here.
A visual example might help: Place some sugar cubes in a cup with coffee(not dissolved) versus dissolve them first before you put them in your drink. The sugar dissolves faster because it has been mixed with hot liquids so their particles can get closer to each other without being repelled by the strong charge on each molecule. Again though -water isn’t mixing well with hydrocarbons at all no matter what temperature or pressure you have them at.
This is because the water molecules are going to be polar and as they come together, the stronger of the two forces wins. In this case, water is a lot more strongly hydrophilic than hydrocarbons are (readily soluble in water). The strength and polarity also play into how quickly they mix but that’s not what we’re talking about here.
By adding different chemicals like ethers or alcohols with high boiling points you can break up these large clusters so they start mixing better – making for some interesting applications such as when used in hydraulic fracturing where there has been an increase in earthquakes due to drilling fluid injection pressure change on rock formations which causes cracks and creates new pathways for gas formation through the rock strata. Now that we know the background, let’s take a closer look at the different types of hydrocarbons.. -alkanes: alkanes are made up of only hydrogen and carbons. They’re also called paraffins which usually refers to those in commercially available products like candles or waxes. The simplest is just one carbon molecule with nothing else attached but there can be more than one – for example methane gas (CH_ _ __ ) has two hydrogens and four carbons while octane fuel (C_-__) has eight carbons with 18 hydrogens total. The higher number of hydrogen atoms means these compounds have lower boiling points because they’re lighter so when you try to boil them off, it happens faster