MIXTURES B.3

Mixture 2 or more substances physically combined: Each retains a separate identity Substances combined can be separated by physical means

Heterogeneous mixture Not uniform throughout Not uniform throughout Examples: Examples: Solids: salt and pepper, raisin bread, granite, wood, etc Solids: salt and pepper, raisin bread, granite, wood, etc Liquids: suspensions and colloids Liquids: suspensions and colloids

Suspensions Mixtures containing large, easily seen particles Particles “settle out” Examples: Vinegar & oil dressing, paint, etc.

Colloids Heterogeneous mixtures composed of intermediate-sized particles Liquid appears cloudy! Examples: Milk, mayo, fog, etc.

Homogeneous mixtures Uniform throughout! All solutions are homogeneous! Examples:sugar water, salt water, gasoline, etc.

2 parts of a solution: Solute: the substance to be dissolved / smallest amount Solvent: dissolving agent / greatest amount

Examples of solutions Kool aid powder (solute) + water (solvent) = Solution

Particle size Suspensions > colloids > solutions

Suspensions Don’t need a microscope to identify Particles are large enough to see with “naked” eye

Colloids Small particles seen only with microscope Cannot see particles without microscope

Solutions Particles too small to be seen even under a microscope

Tyndall effect Visible “path of light” light is reflected Particles must be large enough to reflect the light

Which mixture(s) will show Tyndall effect? Suspensions & colloids Why don’t solutions ever exhibit a Tyndall effect? Particles are too small