Cohesion and Adhesion

Explain why the water evaporated more slowly?

Because

Surface Tension

Behavior that results from cohesion molecules at surface of liquid don't have other like molecules on all sides of them (polar=different charged ends)

What is "salting out" a soap

When you separate the soap from the glycerol and saturated NaCl solution is added

Capillary Action

Combination of cohesion and adhesion The thinner the tube the farther up tube the water will fill

Wetting Agent

Increases adhesion and decreases cohesion

Why does acetone have less cohesion?

The acetone is nonpolar meaning it will spread and disperse across the skin because it is also nonpolar

acetone

evaporates faster

water

evaporates slower

acetone

nonpolar molecules

skin

nonpolar molecules

Unsaturated fats

normally liquids have double bonds in the hydrocarbon tail -C=C-C

water

polar molecules

water

show greater cohesion

acetone

shows greater adhesion

Saturated fat

solids at room temperature C-C-C-H

acetone

spreads out

water

stays beaded up

Surfactants

substances (chemicals) that allow insoluble substances to come into closer physical contact

Adhesion

the property of different molecules or surfaces clinging to each other

Cohesion

the property of molecules of the same substance sticking to each other due to mutual attraction

Detergent water

Adhesive Wetting Agent