[azn_ninja]

My freshman chemistry is ridiculous because the professor words his questions vaguely.
Which of the following is true regarding an emulsion? Check all that apply. A. it is a mixture of materials dissolved in one another B. its stability can be enhanced with an emulsifying agent C. it is composed on two components of unlike polarities D. it is composed of one hydrophobic and one hydrophilic material.
I picked B and C and I got the question wrong. The answer is B,C, and D. But I thought not all emulsions contain one hydrophobic and one hydrophillic material? Am i wrong?

[khemauck]

You said yourself that emulsifiers help stabilize an emulsion. An emulsifier works because it has a hydrophobic end and a hydrophilic end. Take for example oil and water: the hydrophilic end of the emulsifier dissolves in the water and the hydrophobic end in the oil, preventing the two from separating.

An emulsion is defined as a 'hydrophobic colloid system'.