Why does a substance containing only long hydrocarbon chains would not be a good emulsifer for mixtures of water and oil?

Answer 1

Water is a polar solvent, hydrocarbons(oli) non-polar solvents. An emulsifier must be both polar and non-polar, that is , one end of the molecule is polar and will bond with water and the other end non-polar and capable of bonding with the hydroncarbon.

Answer 2

An emulsifier "ties together" substances of differing polarities. Water is very polar and would attract ionically bonded substances. Oil is very hydrophobic and would thus need something very non-polar to attract it. The ideal emulsifier for oil and water would thus have a very non-polar tail and an ionic (very polar) head. A substance with only ionic bonds would only attract the water and not the oil and would thus be a very poor emulsifier.

Answer 3

Long hydrocarbon chains are nonpolar and hydrophobic, making them unable to interact with water molecules. As a result, they cannot form stable interactions with both water and oil molecules to create a stable emulsion. Emulsifiers need to have both hydrophobic and hydrophilic regions to efficiently stabilize water and oil mixtures.