Like dissolve like?

like dissolve like mean polar solvent can dissolve polar substance or non-polar solvent can dissolve non-polar substance

alkanol,with general formula C(n)H(2n+1)OH, is a typical example, which contain a non-polar alkyl group( carbon chain) and a polar hydroxide group(OH-).

if the carbon chain of alkanol is short,for example: methanol and ethanol, it can dissolve in both water and oil. if the carbon chain is long, itcan only dissolve in oil only.

for alkanol, it contains a "hydroxyl group(-OH)" but not "hydroxide group".

I don't want to repeat" how like dissolve like". But when one substance has structure such as soap which is made from adding caustic soda to oil so it has a body of oil but the tail is a sodium anion. It can dissolve in water & oil. This class of substance is called surfactants. It can emulsify oil in water or water in oil. It can reduce the surface tension of water making it can be used to wash dirty. Hence it is main ingradient to cleaning products. Because of this special property, it finds a lot of applications in industry.