A mixture of two or more liquids that are generally immiscible at normal conditions is called emulsion.
To stabilize the emulsion a third substance is added to them to make the two liquids miscible with each other is called an emulsifying agent or emulsifier.
Example- Emulsifying agent in (Butter) w/o emulsion is Lampblack or soot ,heavy metals.
Example- Emulsifying agent in (Milk ) O/w emulsion is Milk protein.
Final Answer:-
Emulsifying agent is a substance which is added to the emulsion to prevent it from separating into different phases thus provides stability to the emulsion.
It promotes the mixing of two immiscible liquids.
