The difference between water-soluble and fat-soluble

Our body cannot do without the support of various vitamins. Once a certain vitamin is deficient, certain symptoms will appear. At this time, we can supplement it through medication to supplement the vitamins that the body lacks. There are two types of vitamins, one is water-soluble and the other is fat-soluble. As the name suggests, one is soluble in water and the other is soluble in fat. The following introduces the difference between water-soluble and fat-soluble.

Fat soluble

It refers to the property that a substance can dissolve in non-polar solvents (such as benzene, ether, carbon tetrachloride, petroleum ether, etc.). Fat-soluble substances usually have longer carbon chains in their molecules.

For example: alkanes, fatty acids, oils, fats, etc.

Generally speaking, organic substances with more than six carbon atoms in their molecules, such as alcohols, aldehydes, ketones, acids, etc. with more than six carbon atoms, are often not easily soluble in water but are fat soluble. Generally, charged particles are poorly lipid soluble. The fat solubility of a substance can be explained by the principle of like dissolves like, because solvents are generally non-polar organic substances, solutes that easily dissolve in them are generally non-polar organic substances, while polar solutes and inorganic substances are generally less fat-soluble. In organisms, fat-soluble substances can pass through cell membranes.

Water Solubility

In a narrow sense, it refers to the solubility of a substance in water; in a broad sense, it refers to the solubility of a substance in polar solvents.

The molecules of water-soluble substances usually contain polar groups such as -OH, -SO3H, -NH2, -NHR, -COOH, etc. or carbon chains that are not too long. Water is the cheapest solvent, with abundant sources and no pollution. Water-soluble polymers dissolve in water because hydrogen bonds are formed between water molecules and the polar side groups of the polymer. The dissolution of water-soluble polymers has an important condition, that is, the solubility parameters of the solute and the solvent must be similar, but this is only a necessary condition for dissolution but not a sufficient condition. The influence of the crystal structure of the polymer must also be considered.