Surfactants

Which of these is the best definition for surface tension?

• A force caused by hydrogen bonds of molecules

• A force acting to increase surface area of the liquid

• A force that explains surfactant behaviour

• A force caused by cohesive forces between molecules

What is a surfactant?

• A molecule that does not adsorb at surfaces

• A substance that prevent bubble formation

• A molecule that reduces surface tension of a liquid

• A substance that is always water soluble

If we reduce the carbon chain length of a surfactant from 12 to 10 we will...

• need less surfactant to reduce surface tension of a liquid

• need more surfactant to reduce surface tension of a liquid

• decrease the solubility of the surfactant in water

• maintain a surface tension of water at 72 mN/m

What does CMC stand for?

• critical micellar concentration

• colloidal minimum concentration

• colloidal micellar concentration

• critical minimum concentration

What are micelles?

• surfactant molecules in any solvent

• spherical aggregates of surfactant in solution

• aggregates of precipitated solids in water

• spherical aggregates of polymers in solution